Operating Expenses

12 Months Ended

Dec. 31, 2019

Operating Expenses

Operating Expenses

6.     Operating expenses

Costs of services

Year ended December 31,	2019		2018		2017
Ancillary and logistical service expenses	$	59,252	$	66,576	$	54,176
Employee compensation expenses		50,093		41,391		35,440
Buildings, facilities and technology expenses		7,865		9,477		8,359
Travel, advertising and promotion expenses		31,652		27,606		23,994
Other costs of services		16,115		14,008		11,220
	$	164,977	$	159,058	$	133,189

SG&A expenses

Year ended December 31,	2019		2018		2017
Employee compensation expenses	$	246,028	$	249,115	$	208,370
Buildings, facilities and technology expenses		61,177		60,930		53,151
Travel, advertising and promotion expenses		38,248		36,728		30,440
Professional fees		15,572		16,768		13,522
Other SG&A expenses		21,364		19,135		17,787
	$	382,389	$	382,676	$	323,270

6.     Operating expenses (continued)

Acquisition-related costs

Acquisition-related costs consist of operating expenses directly incurred as part of a business combination, due diligence and integration planning related to the IronPlanet acquisition (note 29), and continuing employment costs that are recognized separately from our business combinations.

Year ended December 31,	2019		2018		2017
IronPlanet:
Other acquisition-related costs	$	82	$	2,944	$	34,653
Other acquisitions:
Continuing employment costs		128		2,091		3,418
Other acquisition-related costs		567		58		201
	$	777	$	5,093	$	38,272

Depreciation and amortization expenses

Year ended December 31,	2019		2018		2017
Depreciation expense	$	29,112	$	29,021	$	28,337
Amortization expense		41,389		37,593		24,357
	$	70,501	$	66,614	$	52,694

During the year ended December 31, 2019, depreciation expense of $410,000 (2018: $494,000; 2017: $1,207,000) and amortization expense of $27,944,000 (2018: $18,996,000; 2017: $11,662,000) were recorded relating to software.