Note 7 - Income Taxes - Schedule of Effective Income Tax Rate Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020
Federal tax benefit at statutory rate	$ 3,338	$ 3,645
Federal tax benefit at statutory rate, percentage	21.00%	21.00%
State tax benefit net of federal	$ 25	$ 44
State tax benefit net of federal, percentage	0.20%	0.30%
Foreign rate differential	$ 7	$ 6
Foreign rate differential, percentage	0.00%	0.00%
Stock warrant costs	$ 1,413	$ 493
Stock warrant costs, percentage	8.90%	2.80%
Other permanent differences	$ (77)	$ (63)
Other permanent differences, percentage	(0.50%)	(0.40%)
Permanent provision to return items	$ 344	$ 361
Permanent provision to return items, percentage	2.20%	2.10%
Stock compensation change	$ (37)	$ 12
Stock compensation change, percentage	(0.20%)	0.10%
Uncertain tax provision	$ (57)	$ (48)
Uncertain tax provision, percentage	(0.40%)	(0.30%)
Other	$ 0	$ (1)
Other, percentage	0.00%	0.00%
Increase in valuation allowance	$ (4,956)	$ (4,449)
Increase in valuation allowance, percentage	(31.20%)	(25.60%)
Total tax (expense) benefit	$ 0	$ 0
Total tax (expense) benefit, percentage	0.00%	0.00%

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Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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