On September 3, 2019, the Company acquired 100% of the outstanding shares of GFB Holdings, Inc. (“GetFeedback”), including its wholly-owned subsidiary GetFeedback, Inc., a customer experience management company that offers purpose-built solutions to its customers and understands and improves customer experience through the creation of customized branded surveys.

The Company paid approximately $68.3 million for the acquisition, which consisted of (i) cash consideration of approximately $61.5 million (net of cash acquired of approximately $0.7 million) and (ii) 376,333 shares of the Company’s common stock with a fair value of $16.24 per share on the acquisition date.

Based on their estimated fair values, the Company recorded $3.3 million of net tangible liabilities, $17.7 million of identifiable intangible assets (primarily customer relationships and developed technology) and $53.9 million of goodwill.

On April 1, 2019, the Company acquired 100% of the outstanding shares of Usabilla Holding B.V. (“Usabilla”), a voice of customer technology company headquartered in the Netherlands that offers its customers products to help improve their customers’ online experience by generating and processing user feedback via targeted surveys on websites, in mobile apps and by email.

The Company paid approximately $84.3 million for the acquisition, which consisted of (i) cash consideration of approximately $53.1 million (net of cash acquired of approximately $1.1 million) and (ii) 1,644,413 shares of the Company’s common stock with a fair value of $18.30 per share on the acquisition date. Additional consideration of 299,798 shares of the Company’s common stock was issued to certain employees of Usabilla and was not included in the purchase price. This additional consideration will be recognized as post-acquisition compensation expense over the related requisite service period of three years.

Based on their estimated fair values, the Company recorded $2.9 million of net tangible liabilities, $15.1 million of identifiable intangible assets (primarily developed technology) and $72.1 million of goodwill.

Pro forma results of operations for these acquisitions have not been presented because they are not material to the consolidated results of operations, either individually or in the aggregate.

The measurement period for the valuation of assets acquired and liabilities assumed ends as soon as information on the facts and circumstances that existed as of the applicable acquisition date becomes available but does not exceed 12 months from the acquisition date. The measurement periods have closed for the acquisitions of Usabilla and GetFeedback as of December 31, 2020.

The Company has incurred incremental expenses related to the above acquisitions of $1.7 million, which are included in general and administrative expenses in the consolidated statements of operations for the year December 31, 2019.

As of December 31, 2020 and 2019, intangible assets, net consisted of the following:

	December 31, 2020							December 31, 2019
(in thousands)	Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount		Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount
Customer relationships	$	23,804	$	(12,448	)	$	11,356	$	25,594	$	(9,712	)	$	15,882
Trade name		2,824		(1,285	)		1,539		2,711		(763	)		1,948
Developed technology		20,881		(12,569	)		8,312		27,547		(12,227	)		15,320
Acquisition intangible assets, net	$	47,509	$	(26,302	)	$	21,207	$	55,852	$	(22,702	)	$	33,150

Amortization expense was $12.6 million, $9.0 million and $4.3 million during the years ended December 31, 2020, 2019 and 2018, respectively.

The decrease in gross acquisition intangible assets is due to the removal of $9.7 million of fully amortized acquisition intangible assets during the fourth quarter of 2020.

Balance as of December 31, 2018	$	336,861
Additions		125,981
Foreign currency translation		85
Balance as of December 31, 2019		462,927
Foreign currency translation		5,837
Balance as of December 31, 2020	$	468,764

As of December 31, 2020 and 2019, capitalized internal-use software consisted of the following:

(in thousands)	December 31, 2020			December 31, 2019
Gross capitalized internal-use software	$	50,833		$	61,130
Less: Accumulated amortization		(21,371	)		(27,974	)
Capitalized internal-use software, net	$	29,462		$	33,156

Amortization expense related to capitalized internal-use software was $14.2 million, $15.6 million and $21.7 million during the years ended December 31, 2020, 2019 and 2018, respectively, and is included in cost of revenue in the consolidated statements of operations.

The decrease in gross capitalized internal-use software is due to the removal of $20.8 million of fully amortized capitalized internal-use software during the fourth quarter of 2020, offset by current year additions.

As of December 31, 2020, future amortization expense by year is expected to be as follows:

(in thousands)	Capitalized internal-use software, net		Acquisition intangible assets, net
2021	$	10,950	$	10,299
2022		6,963		5,121
2023		1,584		1,928
2024		—		1,670
2025		—		1,389
Thereafter		—		800
Total amortization expense	$	19,497	$	21,207

Future capitalized internal-use software amortization excludes $10.0 million of costs which are currently in the development phase.