Note 2 - Revenue from Contracts with Customers - Deferred Costs of Revenue Balances Included in Prepaid Expenses (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Balance, deferred costs of revenue	$ 89,068	$ 453,607
Defered costs added	17,406	181
Deferred costs expensed	(75,223)	(207,437)
Balance, deferred costs of revenue	$ 31,251	$ 246,351