Note 3 - Balance Sheet Components - Summary of Balance Sheet Amounts (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Cash	$ 12,080	$ 17,281
Cash equivalents	58,583	66,562
Cash and cash equivalents	70,663	83,843
Restricted cash	69	522
Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Ending Balance	70,732	84,365
Inventories:
Finished goods	4,304	4,476
Raw materials	769	873
Reserve for obsolescence	(84)	(92)
Inventory, Net, Total	4,989	5,257
Other accrued expenses:
Sales returns	89	137
Employee-related expense	728	988
Warehousing, inventory-related and other	504	808
Accrued Liabilities, Current, Total	1,321	1,933
Deferred revenue:
Deferred revenue	5,254	8,536
Unshipped Product [Member]
Deferred revenue:
Deferred revenue	3,400	6,525
Auto ship advances [Member]
Deferred revenue:
Deferred revenue	1,771	1,901
Product and Service, Other [Member]
Deferred revenue:
Deferred revenue	$ 83	$ 110