Exhibit 99.1

 Rimini Street, Inc. Investor Presentation  September 5, 2017 

 “Rimini Street” is a registered trademark of Rimini Street, Inc., and Rimini Street, the Rimini Street logo, and combinations thereof, and other marks marked by TM are trademarks of Rimini Street, Inc. ("Rimini“, the “Company”). All other trademarks remain the property of their respective owners, and unless otherwise specified, Rimini claims no affiliation, endorsement, or association with any such trademark holder or other companies referenced herein.Investor PresentationThis communication is for informational purposes only and has been prepared to assist interested parties in making their own evaluation with respect to the proposed potential business combination between Rimini and GP Investments Acquisition Corp. (“GPIAC”) and related transactions and for no other purpose. The information contained herein does not purport to be all-inclusive. The data contained herein is derived from various internal and external sources. No representation is made as to the reasonableness of the assumptions made within or the accuracy or completeness of any projections, modelling or back-testing or any other information contained herein. Any data on past performance, modeling or back-testing contained herein is no indication as to future performance. Neither Rimini nor GPIAC assumes any obligation to update the information in this communication.Forward Looking StatementsCertain statements included in this communication are not historical facts but are forward-looking statements for purposes of the safe harbor provisions under The Private Securities Litigation Reform Act of 1995. Forward-looking statements generally are accompanied by words such as “believe,” “may,” “will,” “estimate,” “continue,” “anticipate,” “intend,” “expect,” “should,” “would,” “plan,” “predict,” “potential,” “seem,” “seek,” “future,” “outlook,” and similar expressions are intended to identify forward-looking statements. These forward-looking statements include, but are not limited to, statements regarding 2017 and 2018 net revenue estimates and forecasts of other financial and performance metrics, projections of customer savings, projections of market opportunity, expectations regarding the proposed business combination, including the expected benefits of the proposed business combination, and expectations regarding Adjusted EBITDA and Unlevered Free Cash Flow growth. These statements are based on various assumptions and on the current expectations of GPIAC and Rimini management and are not predictions of actual performance. These forward-looking statements are subject to a number of risks and uncertainties, including adverse litigation developments; the inability to refinance existing debt on favorable terms; GPIAC’s and Rimini’s respective businesses and the proposed potential transaction; the loss of one or more members of GPIAC’s or Rimini’s management team; the inability of the parties to successfully or timely consummate the proposed potential transaction, including the risk that any required regulatory approvals are not obtained, are delayed or are subject to unanticipated conditions that could adversely affect the combined company or the expected benefits of the proposed potential transaction or that the approval of the stockholders of GPIAC and/or the stockholders of Rimini for the transaction is not obtained; failure to realize the anticipated benefits of the proposed potential transaction, including as a result of a delay in consummating the proposed potential transaction or a delay or difficulty in integrating the businesses of GPIAC and Rimini; uncertainty as to the long-term value of GPIAC common stock; those discussed in GPIAC’s Annual Report on Form 10-K for the year ended December 31, 2016 under the heading “Risk Factors,” as updated from time to time by GPIAC’s Quarterly Reports on Form 10-Q and other documents of GPIAC on file or to be filed with the Securities and Exchange Commission (“SEC”) or in the joint proxy statement/prospectus that has been filed with the SEC by GPIAC. If the risks materialize or our assumptions prove incorrect, actual results could differ materially from the results implied by these forward looking statements. There may be additional risks that neither GPIAC nor Rimini presently know or that GPIAC and Rimini currently believe are immaterial that could also cause actual results to differ from those contained in the forward-looking statements. In addition, forward-looking statements provide GPIAC’S and Rimini’s expectations, plans or forecasts of future events and views as of the date of this communication. GPIAC and Rimini anticipate that subsequent events and developments will cause GPIAC’s and Rimini’s assessments to change. However, GPIAC and Rimini specifically disclaim any obligation to update any forward looking statements contained herein. These forward-looking statements should not be relied upon as representing GPIAC’s and Rimini’s assessments as of any date subsequent to the date of this communication. Any data on past performance, modeling or back-testing contained herein is no indication as to future performance.No Offer or SolicitationThis communication does not constitute an offer to sell or a solicitation of an offer to buy, or the solicitation of any vote or approval in any jurisdiction in connection with a proposed potential business combination between Rimini and GPIAC or any related transactions, nor shall there be any sale, issuance or transfer of securities in any jurisdiction where, or to any person to whom, such offer, solicitation or sale may be unlawful.Important Information for Investors and StockholdersIn connection with the transactions referred to in this communication, on June 30, 2017, GPIAC filed its Registration Statement with the SEC and on August 9, 2017, and August 30, 2017, GPIAC filed amended Registration Statements with the SEC containing a preliminary joint proxy statement of GPIAC and Rimini that also constitutes a preliminary prospectus of GPIAC. After the registration statement is declared effective GPIAC and Rimini will mail a definitive joint proxy statement/prospectus to stockholders of GPIAC and stockholders of Rimini Street.This communication is not a substitute for the joint proxy statement/prospectus or registration statement or for any other document that GPIAC may file with the SEC and send to GPIAC's stockholders and/or Rimini Street's stockholders in connection with the proposed transactions. INVESTORS AND SECURITY HOLDERS ARE URGED TO READ THE JOINT PROXY STATEMENT/PROSPECTUS AND OTHER DOCUMENTS FILED WITH THE SEC CAREFULLY AND IN THEIR ENTIRETY WHEN THEY BECOME AVAILABLE BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION. Investors and security holders may obtain free copies of the joint proxy statement/prospectus (when available) and other documents filed with the SEC by GPIAC through the website maintained by the SEC at http://www.sec.gov. Copies of the documents filed with the SEC by GPIAC are available free of charge by contacting GPIAC at 150 E. 52nd Street, Suite 5003, New York, New York 10022, Attn: Investor Relations.Participants in the SolicitationGPIAC and Rimini Street and their respective directors and certain of their respective executive officers may be considered participants in the solicitation of proxies with respect to the proposed transactions under the rules of the SEC. Information about the directors and executive officers of GPIAC is set forth in its Annual Report on Form 10-K for the year ended December 31, 2016, which was filed with the SEC on March 16, 2017. Additional information regarding the participants in the proxy solicitations and a description of their direct and indirect interests, by security holdings or otherwise, will be included in the joint proxy statement/prospectus and other relevant materials to be filed with the SEC when they become available. These documents can be obtained free of charge from the sources indicated above.Non-GAAP Financial MeasuresThis communication includes non-GAAP financial measures, including EBITDA and Adjusted EBITDA, which are supplemental measures of performance that are neither required by, nor presented in accordance with U.S. generally accepted accounting principles ("GAAP"). EBITDA is calculated as earnings before interest and taxes plus depreciation and amortization. Adjusted EBITDA is calculated as EBITDA, excluding the impact of certain items that Rimini management does not consider representative of its ongoing operating performance. A reconciliation of such non-GAAP financial measures to GAAP financial measures is included as an appendix hereto.Rimini and GPIAC believe that such non-GAAP financial measures provide useful supplemental information to their respective board of directors, management teams and investors regarding certain financial and business trends relating to Rimini's financial condition and results of operation. Rimini and GPIAC believe such measures, when viewed in conjunction with its consolidated financial statements, consistency and comparability with Rimini’s past financial performance, facilitate period-to-period comparisons of operating performance and may facilitate comparisons with other companies. Undue reliance should not be placed on these measures as Rimini's only measures of operating performance, nor should such measures be considered in isolation from, or as a substitute for, financial information presented in compliance with GAAP. Non-GAAP financial measures as used in respect of Rimini may not be comparable to similarly titled amounts used by other companies.  Legal Notice 

 Presenters  Seth RavinFounder, Chairman, & CEO  Thomas SabolSVP, CFO  Antonio BonchristianoCEO  Andrew FleissManaging Director 

   GP Investments Acquisition Corp. (NASDAQ: “GPIA”; “GPIAU”; “GPIAW”) has entered into a definitive agreement to merge with Rimini Street, Inc. (“Rimini Street”)Rimini Street is a global provider of enterprise software support products and servicesFollowing consummation of the transaction, GPIAC will be renamed Rimini Street, Inc. and intends to trade on NASDAQ Global Markets under the new ticker symbol “RMNI”Transaction highlightsHigh growth company (30%+ net revenue CAGR 2014A – 2018E(1)) with strong, expanding gross profit percentages (55% in 2015A; 58% in 2016A) targeting a large addressable marketEnterprise value of approximately $830 million; equity value of $812 million(2) Attractive purchase valuation at 3.2x 2018E net revenue of $260 million(1) (>50% discount to median of peers(3))Confidence in continued growth potential of the combined public entityExisting owners of Rimini Street will roll 100% of their ownership in the transaction; cash used to pay down debtRimini Street shareholders will own approximately 76% of the combined company, and current GPIAC shareholders will own approximately 24%(2)An affiliate of GPIAC’s sponsor will backstop up to $35 million via the purchase of common stock at a price of $10.00 per shareThe transaction is expected to close September 2017  (1): 2018E net revenue calculated as a midpoint of guidance range, refer to page 22 for guidance ranges.(2): Based on fully-diluted shares outstanding of 81.2 million at a $10.00 share price, expected debt of $50.0 million and cash of $32.4 million at close, and zero redemptions from cash in trust.(3): Peers are small / mid cap ERP software companies.  4  Transaction Overview 

 $5B+ capital raised, 50+ investments & 20+ capital market transactions$30B+ assets under management  Investment Highlights  Large Market Opportunity  Compelling Client Value Proposition  High Growth, Predictable Business Model   Significant Free Cash Flow Generation  Diverse & Prominent Client Base  Experienced Management Team  World Class Financial Sponsors  Attractive Valuation  $81 billion TAM for on-premise maintenance opportunities$6 billion TAM for supplemental cloud premium maintenance opportunities  Clients can save up to 90% in total maintenance costs by replacing vendors with Rimini StreetSupports custom & standard code with no forced upgrades  46 consecutive quarters of net revenue growth, 30%+ net revenue CAGR from 2014A to 2018E(1)Approximately 100% subscription and recurring net revenue, 90%+ Revenue Retention Rate(2)  Pro-forma capital structure will further enable significant free cash flow(3) generationUnlevered Free Cash Flow Yield in 2018E of ~6%(4)   Proven management team with experience at leading companies including:  (1): 2018E net revenue calculated as a midpoint of guidance range, refer to page 22 for guidance ranges.(2): See Revenue Retention Rate definition on page 39.(3): Unlevered Free Cash Flow is a non-GAAP measure, see Unlevered Free Cash Flow historical reconciliation on page 37.(4): Unlevered Free Cash Flow Yield is a non-GAAP measure, see definition on page 40. 2018E Unlevered Free Cash Flow calculated as a midpoint of guidance range, refer to page 22 for guidance ranges.  Transaction values Rimini Street at a meaningful discount to public comparablesImplied EV / 2018E net revenue(1) multiple is < 50% of the median of small / mid cap ERP peers 

 Company Overview 

   Company Snapshot    Founded: 2005Global Headquarters: Las Vegas, NVEmployees: Approximately 900Active Clients: 1,330+Global Offices: Beijing, Bengaluru, Frankfurt, Hyderabad, London, Melbourne, New York, Osaka, Paris, San Francisco Bay Area, São Paulo, Seoul, Singapore, Stockholm, Sydney, Tel Aviv and Tokyo   Strong Net Revenue Growth Profile  Many Supported Products  Global Platform  Rimini Street is a global provider of enterprise software support products and services  Diversified Net Revenue Sources  By Industry (# Clients)(2)  By Geography ($ Value)(2)  Sybase  2014A – 2018E CAGR 30%+   (1)  (1): 2017E and 2018E shown as the low and high end of the net revenue guidance ranges, see page 22.(2): Through 1H 2017A.  $210    $270  (1) 

 Highly-Experienced Management Team    Thomas ShaySVP & CIO    Seth RavinFounder & CEO    Daniel B. WinslowSVP & General Counsel    David RoweSVP & CMO    Sebastian GradyPresident     Kevin MaddockSVP, Global Sales    Nancy LyskawaSVP, Global Client Onboarding    Thomas SabolSVP, CFO                Brian SlepkoSVP, Global Service Delivery 

                     Platforms Supported  Proven History of Value Creation as a Disruptor 

 “SAP upgrades to subsequent versions provide few or no advantages for the user. We wanted to continue using our current SAP R/3 4.7 version, while we explore alternatives for the future.”  “We were faced with the tough decision of going through a forced upgrade to SAP ECC 6.0 or having to deal with the downsides of customer-specific maintenance. Once we discovered Rimini Street, we were extremely pleased”“One of our goals was to become more flexible in our PeopleSoft applications’ upgrade strategy to decide when and how we upgrade. Thanks to Rimini Street, we’ve successfully done that.”  “60% of respondents see no strong business case to migrate to Oracle Cloud/Fusion applications.”“Fusion is not a full functional replacement for EBS …there are many industry use cases that Fusion wasn't built for as the core apps platform.”  High Cost, Low Value for Maintenance Dollars  Limited Innovation in Core ERP  No Choice – Forced Upgrades  No Business Case for Oracle ERP Cloud   1  “Enterprises have come to believe that there is not enough value received for the high annual cost of the ERP vendor's maintenance agreement.”  “We analyzed what we were paying and what we were getting, and the service levels weren’t up to par with what we needed from the standpoints of issue turnaround and accuracy.”  2  3  4  "EBS 12 didn’t have any features our business needed. We were very conscious that we needed to identify an organization to support our company-wide EBS 11i, including payroll.”  The Enterprise Software Maintenance Support Problem 

 The Rimini Street Solution      Software Vendor    Rimini Street Independent Support  Focus    Vendor-Centric    Client-Centric  Cost Model    22% Annual Fee    11% Annual Fee  Support Coverage    Vanilla Software Only    Vanilla Software and All Custom Code  Delivery Model    Book Trained Help Desk    Experienced Engineers With an Average of 15+ Years Proven Track Record Assigned to Each Client  Upgrades    Forced Upgrades    Upgrade Only If Desired and When Ready  Innovation    Vendor Only    Vendor and Best-of-Breed Options  Flexibility    Vendor Lock-In    Full Ecosystem of Vendor Choices  By replacing Oracle, SAP, Microsoft and IBM maintenance, enterprises can enjoy higher levels of support, save up to 90% on their total maintenance costs, and free up funds that can be used to invest in new initiatives 

 Case Study – NCH Corporation  NCH saving 83% compared to Oracle’s annual support program costs with switch to Rimini Street Support    $1,000,000  $1,600,000  $330,000  $20,000  $0  $0  $0  $500,000  $3,000,000  50% saving on $1,000,000  Savings by avoiding two upgrades over 10 years  Free full-time employees supporting custom code  Free full-time employees from testing and self-support  Annual Costs with Rimini Street Support  Annual Costs with Software Vendor Support  “By avoiding forced upgrades with independent support, we were able to fund strategic projects that were critical for the business including rolling out EBS globally to 36 countries and making important investments in sales and service mobility tools.”Former NCH IT Director – Core Applications & Global Support     $2,950,000  $500,000  After Switch to Rimini Street  Actual Maintenance Costs 

             Upgrade Support & Best PracticesEngineers with 15+ Average Years ExperienceHighly Compensated Engineers  Accelerate Globalization Avoid Business DisruptionCapabilities for ~200 Countries  Expand License RightsPurchase New ProductsMergers & Acquisitions  Invest in Systems of EngagementChoose Best of Breed SolutionsBetter Functionality, Lower Cost  Migrate HW/OS/MW/DBUpgrade OS/DB/MW/BrowsersAdd Mobile Devices  Rimini Street: A Long-Term Partner for Clients  Clients continue evolving, expanding and innovating their organizations and systems under Rimini Street Support    Perform Upgrades  Expand Capabilities  Change Infrastructure        Roll-Out Globally  Innovate with Hybrid IT  Over 150 Upgrades  Support 120+ Countries   Licenses and Products  Run 15+ More Years  Innovate Around Edges  Use Cases for Growth with Clients 

 Overview of Market Opportunity 

 $87 Billion Market Opportunity   $15 Billion TAM for Current and Planned Rimini Street Products  $14.5 BillionIBM + Microsoft + Oracle + SAP    Total Rimini Street Annual Market Opportunity(1)  Currently Supported Products  $360 Million(2)Cloud / SaaS  SAP Business SuitePeopleSoftSiebelJD EdwardsOracle EBSOracle RetailOracle Agile PLMOracle ATG  Business ObjectsHana DatabaseHyperionIBM DB2Microsoft SQL ServerOracle DatabaseOracle MiddlewareSAP Sybase  Salesforce.comWorkday  Planned Next Products  $360 MillionSalesforce + Workday  (1): Based on data from Forrester Research’s “The Midyear Global Tech Market Outlook for 2016 to 2017” as of September 16, 2016 and Rimini Street’s own calculations. On-premise Maintenance is estimated to be a $162 billion annual market by Forrester.(2): Rimini Street bottom-up estimate.  $7.1 Billion(2)On-Premise Applications  $7.4 Billion(2)Technology and Business Intelligence        $81 BillionOn-Premise Maintenance Opportunity      $6 BillionSupplemental CloudPremium Maintenance       

 Competitive Landscape  Independent Support Vendors      Software Vendors  Primary Competitors   Few competitors and a defensible market position  Substantial cost savingsSupport for all custom codeCustom global tax, legal and regulatory supportExcellent service experience (4.8 out of 5 client satisfaction score)(1)Guaranteed no required major upgrade for minimum fifteen (15) yearsPreferred proprietary tools, methodologies and processes (and patents pending)  Comprehensive and proven global software support capabilitiesSupport for all custom codeSuperior full ecosystem of extendibility and extensibility solutionsBreadth & proven track record with global tax, legal and regulatory supportGlobal Service Level Agreement – 15 minute guaranteed response 24x7x365Preferred proprietary tools, methodologies and processes (and patents pending)  Why Rimini Street Wins  (1): Automated customer surveys performed by Rimini Street. 

           Growth Drivers  Note: Diagram shown only for illustrative purposes and is not indicative of magnitude of growth driver potential or priority.  Global Expansion  New SaaS Products  New License Products  Existing Clients  Enter additional countriesExpand capabilities in existing countries  Pursue premium support services for SaaS products, including Salesforce and Workday  Add product support for additional software products from SAP, Oracle, and other vendors  Solid core of existing blue chip clients with high renewal rateUpsell / cross-sell additional products & packages to our client base          New Clients  Expand beyond existing number of global sales repsHistory of over 100% average quota attainment    Numerous avenues for future expansion 

 Financial Overview   

 High Growth, Predictable Net Revenue    (1): 2017E and 2018E shown as the low and high end of the net revenue guidance ranges, see page 22.(2): See Revenue Retention Rate definition on page 39.(3): See Backlog definition on page 40.(4): See LTV to CAC definition on page 40.  46 consecutive quarters of net revenue growth100% subscription model with 90%+ Revenue Retention Rate(2) results in highly predictable net revenueBacklog of $300M(3), as of Q2 2017, further bolsters visibilityLTV to CAC(4) of 7.4x as of Q2 2017  Key Statistics  2014A – 2018E CAGR 30%+   (1)    $210    $270  (1) 

 Key Operating Metrics  (1): See Annualized Subscription Revenue definition on page 39.(2): See Revenue Retention Rate definition on page 39.  Revenue Retention Rate(2)  29%    Annualized Subscription Revenue(1)  42%  Gross Profit Percentage  30%  44%    Active Clients 

 (1): EBITDA is a non-GAAP measure, see EBITDA reconciliation on page 37 for historical reconciliation to the closest GAAP measure. (2): Adjusted EBITDA is a non-GAAP measure, see Adjusted EBITDA reconciliation on page 37 for historical reconciliation to the closest GAAP measure.  Historical Financial Performance    Strong net revenue growth across the yearsContinued gross profit percentage expansionDecreased sales & marketing spend as a percentage of net revenue as a result of debt covenantsIncreased Adjusted EBITDA(2) as the business scales  Observations 

 Forward Outlook    Note: High and low of the guidance ranges are rounded to the closest million.(1): Adjusted EBITDA is a non-GAAP measure, see Adjusted EBITDA reconciliation on page 37 for historical reconciliation to the closest GAAP measure. (2): Unlevered Free Cash Flow is a non-GAAP measure, see Unlevered Free Cash Flow reconciliation on page 37 for historical reconciliation to the closest GAAP measure. 

 Substantial, Growing Free Cash Flow     (1): Adjusted EBITDA is a non-GAAP measure, see Adjusted EBITDA reconciliation on page 37 for historical reconciliation to the closest GAAP measure. 2017E and 2018E Adjusted EBITDA calculated as a midpoint of guidance ranges, refer to page 22 for guidance ranges. (2): Unlevered Free Cash Flow is a non-GAAP measure, see Unlevered Free Cash Flow reconciliation on page 37 for historical reconciliation to the closest GAAP measure. 2017E and 2018E Unlevered Free Cash Flow calculated as a midpoint of guidance ranges, refer to page 22 for guidance ranges.  Adjusted EBITDA(1) growth and low CapEx expected to drive growth in Unlevered Free Cash Flow(2)Working capital driven by upfront payments on subscription salesAttractive tax attributes driven by net operating losses (~$190M as of December 2016)With new capital structure following the merger with GPIAC, the Company expects to reduce leverage and interest expense  Key Statistics  (1)  (2) 

 Business Combination Overview   

 (1): See LTV to CAC definition on page 40.    25  Rimini Street has the size, scale, and leading market position to become a compelling public company. GP has strong conviction in Rimini Street’s continued growth potential as it disrupts and redefines a very large established ERP software maintenance marketRimini Street’s growth and margin profile, and strong LTV to CAC(1), are reflective of the Company’s meaningful customer value propositionRimini Street currently has a debt facility that was utilized to fund a court judgment of $124.4M Judgment rendered against Rimini Street for verdict of “innocent infringement” and “violation of state computer access laws”; Court findings, being appealed, required service delivery process changes for some Rimini Street product lines in 2014 and payment of $124.4M to Oracle in 2016The verdict does not prohibit or restrict Rimini Street from providing support services to any client and the trial validated Rimini Street’s legal right to offer independent maintenance services for enterprise software products (including Oracle products)Rimini Street has filed an appeal to overturn the judgment and is seeking return of the full $124.4M; expects the appeal to be resolved by the end of 2018Rimini Street filed a lawsuit against Oracle in 2014, and Oracle has filed counter-claims. The case is in the “discovery” phase; If not settled or dismissed earlier, this litigation is expected to reach trial in 2020 or 2021The combination of GPIAC and Rimini Street is expected to allow the Company to reduce debt and associated service costs, and eliminate restrictive covenants associated with the debt  Transaction Background 

 Pro-forma enterprise value of $830M All existing Rimini Street shareholders will roll 100% of their equity$118M used to pay down Rimini Street’s debt(1)Rimini Street expected to maintain $50M of debtCompletion of the transaction is expected by the end of September    Post-Transaction Ownership(2)  Enterprise Value  Overview  Cash Sources and Uses  ($ millions, except price per share amounts)  ($ millions)  Note: All figures reflect zero redemptions from cash in trust by GPIAC shareholders. Actual results may differ materially. (1): Rimini Street expected debt pre-closing of $164.7 million plus $3.0M of GPIAC promissory notes.(2): Based on fully diluted shares outstanding at $10.00 per share, inclusive of 15.7 million GPIAC shares, 4.3 million founder shares, and 61.2 million shares issuable to current Rimini Street shareholders including option and warrant holders. Treasury stock method applied to Rimini Street warrants and options. Percentage ownership figures rounded to the nearest whole percentage. Excludes 14.7 million outstanding warrants at a strike price of $11.50 per share. (3): Total cash equal to Rimini Street expected cash pre-closing of $15.2 million plus excess cash of $17.2.(4): 2018E net revenue and Adjusted EBITDA calculated as a midpoint of guidance ranges, refer to page 22 for guidance ranges. Adjusted EBITDA is a non-GAAP measure, see Adjusted EBITDA reconciliation on page 37 for historical reconciliation to the closest GAAP measure.   Property of Rimini Street ©2017    26  Transaction Summary 

 Median = 5.2x     Source: Capital IQ as of September 1, 2017. Note: Negative multiples and multiples greater than 75.0x are deemed as “Not Meaningful” or “NM.”(1): Based on an enterprise value of $829.8 million. 2018E net revenue & Adjusted EBITDA calculated as a midpoint of guidance ranges, refer to page 22 for guidance ranges.(2): Adjusted EBITDA is a non-GAAP measure, see Adjusted EBITDA reconciliation on page 37 for historical reconciliation to the closest GAAP measure.   EV / 2018E Net Revenue  EV / 2018E Adj. EBITDA(2)  Large Cap ERP Software  Small / Mid Cap ERP Ecosystem Software  Median = 7.2x  Large Cap ERP Software  Median = 12.7x   Median = 22.1x  (1)  (1)  Small / Mid Cap ERP Ecosystem Software  Valuation Discount vs. Public Comparables… 

   Source: Capital IQ as of September 1, 2017. Note: Negative multiples and multiples greater than 75.0x are deemed as “Not Meaningful” or “NM.”(1): Based on an enterprise value of $829.8 million. Rimini Street 2018E net revenue, Adjusted EBITDA, and Unlevered Free Cash Flow calculated as a midpoint of guidance ranges, refer to page 22 for guidance ranges.(2): Adjusted EBITDA is a non-GAAP measure, see Adjusted EBITDA reconciliation on page 37 for historical reconciliation to the closest GAAP measure. (3): Unlevered Free Cash Flow is a non-GAAP measure, see page 37 for Rimini Street Unlevered Free Cash Flow historical reconciliation to the closest GAAP measure.  EV / 2018E Adj. EBITDA(2) / 2018E Net Revenue Growth  EV / 2018E UFCF(3) / 2018E Net Revenue Growth  Large Cap ERP Software  Small / Mid Cap ERP Ecosystem Software  Median = 1.9x   Median = 2.0x  Large Cap ERP Software  Median = 2.4x   Median = 3.1x  (1)  (1)  Small / Mid Cap ERP Ecosystem Software  …Especially When Adjusted for Growth… 

 Source: Capital IQ as of September 1, 2017.(1): Based on an equity value of $812.1 million. Unlevered Free Cash Flow Yield is a non-GAAP measure, see page 37 for Unlevered Free Cash Flow historical reconciliation to the closest GAAP measure. 2018E Unlevered Free Cash Flow calculated as a midpoint of guidance range, refer to page 22 for guidance ranges.(2): See Unlevered Free Cash Flow Yield definition on page 40.    2018E Unlevered FCF Yield(2)  Large Cap ERP Software  Median = 4.2%   Median = 3.0%  Small / Mid Cap ERP Ecosystem Software  (1)  …With Compelling UFCF Yield vs. Public Comparables 

   2017E Net Revenue Growth  2018E Net Revenue Growth  Source: Capital IQ as of September 1, 2017.(1): 2017E and 2018E net revenue calculated as a midpoint of guidance ranges, refer to page 22 for guidance ranges.  Large Cap ERP Software  Small / Mid Cap ERP Ecosystem Software  Median = 21.0%   Median = 14.5%  Large Cap ERP Software  Median = 7.4%   Median = 15.6%  Small / Mid Cap ERP Ecosystem Software  (1)  (1)  Financial Performance vs. Public Comparables 

 Source: Capital IQ as of September 1, 2017, ECM Analytics, and Renaissance Capital.(1): Based on an enterprise value of $829.8 million. Rimini Street 2018E net revenue calculated as a midpoint of guidance ranges, refer to page 22 for guidance ranges.(2): Rimini Street 2018E gross profit percentage calculated as a midpoint of guidance range, refer to page 22 for guidance ranges.(3): Adjusted EBITDA is a non-GAAP measure, see Adjusted EBITDA reconciliation on page 37 for historical reconciliation to the closest GAAP measure. Rimini Street 2018E Adjusted EBITDA calculated as a midpoint of guidance range, refer to page 22 for guidance ranges.                EV / 2018E Net Revenue  (1)      At Offer  At Current Price  Median at Current Price = 7.8x   2016A-2018E Net Revenue CAGR:  2018E Gross Profit %:  2018E Net Revenue :  2018E Adj. EBITDA Margin:    27.5%  13.1%  62.0%  $260.0  (3)    (1)  (1)  Valuation Discount to Select Recent Software IPOs  EV / 2018E Net Revenue at Offer:  65.6%  (34.7%)  68.2%  $235.6   5.4x  44.3%  (10.7%)  69.2%  $174.2   5.2x  41.7%  (15.3%)  73.6%  $376.9   5.7x  33.4%  26.9%  84.2%  $944.7   4.8x  41.0%  (12.0%)  84.4%  $170.6   4.2x  19.8%  (15.6%)  64.8%  $190.7   3.6x  34.4%   2.4%  80.1%  $222.4   3.7x  (2) 

   Leader in Alternative Investments  Since its foundation in 1993, GP Investments has completed over 50 investments across multiple sectors and over 20 capital markets transactionsOver $5 billion raised from investors worldwide and over $1 billion of proprietary capital invested alongside limited partnersLong history of partnership with high growth companies and a successful track record in the technology spaceFocus on value creation through active management and an operationally-oriented approachAntonio Bonchristiano, CEO of GP Investments, was the Founder & CEO of Submarino which was acquired by B2W, one of the largest eCommerce companies in Latin America  Private Equity Leadership in Technology  Single largest shareholder in Rimini Street45+ year history of private market investments across 30+ countriesCurrently managing $30+ billion of assets as a firmAdams Street Partners’ direct investment teams have partnered with over 220 entrepreneurs and have invested $1.5+ billion since 1972, intently focusing on the areas of technology and healthcareAdams Street Partners invested in Rimini Street in 2009 and has been a trusted advisor with Robin Murray serving on the Rimini Street board  Top Tier Sponsorship with Long Term Investment Horizons 

   Strong and Disruptive Business with 46 Consecutive Quarters of Net Revenue GrowthProven Management Team with Strong Execution HistoryMarket Opportunity of more than $87 Billion and Run-Rate Net Revenues of $200+ MillionTransaction Expected to Improve Balance Sheet, Reduce Leverage, and Position the Company for Accelerated Growth Transaction at a Meaningful Discount to Market Comparables  Opportunity Summary 

 Appendix 

 Additional Comparable Company Benchmark Data    Source: Capital IQ as of September 1, 2017. Note: Negative multiples and multiples greater than 75.0x are deemed as “Not Meaningful” or “NM.”(1): Rimini Street 2017E and 2018E net revenue calculated as a midpoint of guidance ranges, refer to page 22 for guidance ranges.(2): Rimini Street 2018E gross profit percentage calculated as a midpoint of guidance range, refer to page 22 for guidance ranges.(3): Adjusted EBITDA is a non-GAAP measure, see Adjusted EBITDA reconciliation on page 37 for historical reconciliation to the closest GAAP measure. Rimini Street 2018E EBITDA calculated as a midpoint of guidance range, refer to page 22 for guidance ranges.(4): Unlevered Free Cash Flow is a non-GAAP measure, see page 37 for Unlevered Free Cash Flow historical reconciliation to the closest GAAP measure. Rimini Street 2018E Unlevered Free Cash Flow calculated as a midpoint of guidance range, refer to page 22 for guidance ranges.(5): Based on an enterprise value of $829.8 million for Rimini Street. 

 Historical Reconciliations  Note: May not sum due to rounding. 

 Supported Products        Product Lines: ALL Releases: 5.x, 6.0x, 6.3x, 7.0x, 7.5x, 7.7x, 7.8x and 8.x  Product Lines: HCM, FIN, CRM, EPM, SRM, SCM, Public Sector and Campus SolutionsReleases: 7.x, 8.x and 9.x  Product Lines: ALL Releases: MS SQL Server 2008 and later  Product Lines: ALL Releases: 8.0 and later  Product Lines: SAP Adaptive Server Enterprise (ASE), SAP IQ, SAP SQL Anywhere, SAP Advantage Database ServerReleases: ALL  Product Lines: BusinessObjects Enterprise, Advanced Analysis, Interactive Analysis (Web Intelligence), Explorer, Dashboard Design (Xcelsius) and Crystal ReportsReleases: BusinessObjects 6 and later releases  Product Lines: ALL Releases: SAP ECC 6.0 and earlier, BW 3.5, SAP Business Suite – including BI7, SCM, CRM, EWM, PLM and GTS  Oracle Hyperion Planning, Oracle Essbase, Oracle Hyperion Financial Management, Oracle Hyperion Financial Close Management, Oracle Hyperion Strategic Finance, and Oracle Financial Management Analytics  Product Lines: Merchandising Operations Management, Merchandising Planning and Optimization, and Supply Chain Planning and Execution Releases: 10.x and later releases  Product Lines: ALL Releases: ALL  Product Lines: ALL Releases: 9, 10, 11  Product Lines: Majority of the Oracle Fusion Middleware ProductsReleases: Certified in conjunction with supported applications  Product Lines: ALL Releases: Certified in conjunction with supported applications  Product Lines: ALL Releases: 10.7 and later  Product Lines: HCM, Financials, Distribution and ManufacturingReleases: ALL  Sybase  Product Lines: HANA Database and related componentsReleases: ALL 

 Summary of Key Operating Metrics  Active client - Distinct entity, such as a company, an educational or government institution, or a subsidiary, division, or business unit of a company that purchases Rimini Street services to support a specific productGrowth in the number of clients is an indication of the increased adoption of the Company’s enterprise software products and services  Number of Clients  Annualized Subscription Revenue  Gross Profit Percentage  Revenue Retention Rate  The amount of subscription revenue recognized during a quarter and multiplied by fourGives an indication of the revenue that can be earned in the following 12-month period from the Company’s existing client base assuming no cancellations or price changes occur during that period  Actual subscription revenue (dollar-based) recognized in a 12-month period from clients that existed on the day prior to the start of the 12-month period divided by the Company’s annualized subscription revenue as of the day prior to the start of the 12-month periodProvides insight into the quality of Rimini Street’s products and services and the value that the Company’s products and services provide clients  Difference between net revenue and the costs incurred in providing the software products and services divided by net revenueProvides an indication of how efficiently and effectively Rimini Street is operating the business and serving clients 

 Customer Lifetime Value (LTV): Equal to average gross profit percentage over the forecast period per client multiplied by the average customer lifeCustomer Acquisition Costs (CAC): Equal to total sales and marketing costs (excludes Global Client Engagement expenses) in the TTM period divided by the new clients acquired in the same TTM periodLTV to CAC: Equal to LTV divided by CAC, shows the number of times company able to recover the acquisition costs over the lifetime of the customerBacklog: Sum of billed (deferred revenue on balance sheet) and non-cancellable (future revenue not on balance sheet)Unlevered Free Cash Flow (FCF) Yield: Calculated as Unlevered Free Cash Flow / equity value  Glossary