Summary of significant accounting policies (Tables)

12 Months Ended

Dec. 31, 2014

Summary of significant accounting policies

Schedule of estimated useful lives for property and equipment

Computer equipment	2 to 5 years
Software	2 to 5 years
Office equipment	3 to 5 years
Leasehold improvements	The shorter of the estimated useful life or the remaining term of the agreements, generally ranging from 2 to 15 years

Schedule of weighted average assumptions used to calculate the grant date fair values of employee stock option grants

	December 31,
	2014			2013			2012
Expected term (years)		6.25			6.25			5.9
Expected volatility		48.6	%		49.31	%		48.9	%
Risk-free interest rate		1.8	%		1.34	%		0.9	%
Dividend yield		0	%		0	%		0	%

Summary of the entity's revenue by primary revenue source

	Year Ended December 31,
	2014		2013		2012
Revenue:
Retail	$	40,336	$	43,194	$	46,145
DAS		38,259		32,681		30,751
Wholesale—Wi-Fi		15,209		17,261		18,744
Military		4,486		1,260		—
Advertising and other		21,007		12,350		6,866
Total revenue	$	119,297	$	106,746	$	102,506