CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Income Statement [Abstract]
Revenue	$ 20,442	$ 16,821
Cost of goods sold	2,200	1,932
Gross profit	18,242	14,889
Operating expenses:
Sales and marketing	20,922	19,281
Research and development	2,955	2,090
General and administrative	5,940	5,400
Total operating expenses	29,817	26,771
Loss from operations	(11,575)	(11,882)
Interest and other income (expense), net:
Interest income	61	498
Interest expense	(1,064)	(1,231)
Other income (expense), net	336	(157)
Net loss	(12,242)	(12,772)
Other comprehensive income (loss):
Changes in foreign currency translation	(115)	12
Unrealized gain on marketable securities	21	221
Comprehensive loss	$ (12,336)	$ (12,539)
Net loss per share, basic and diluted (in dollars per share)	$ (0.37)	$ (0.47)
Weighted-average shares used to compute basic and diluted net loss per share	32,691,578	27,252,409