Note 21 - Segment Reporting - Summary of Segment Reporting Information (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2021		Mar. 31, 2020		Dec. 31, 2020
Revenues		$ 8,396		$ 4,384
Cost of revenues		9,113		3,485
Total operating expenses		1,098		3,175
Depreciation and amortization expense included in total operating expenses				207
Operating loss		(1,815)		(2,276)
Change in fair value of warrant liabilities		2,507		46
Net (loss)/income		687		(2,310)
Expenditure for long-term assets		1,160		302
Total assets		38,627				$ 20,667
Corporate, Non-Segment [Member]
Revenues				645
Cost of revenues
Total operating expenses		511	[1]	2,148	[2]
Depreciation and amortization expense included in total operating expenses		1		1
Operating loss		(511)		(1,503)
Change in fair value of warrant liabilities		2,507		46
Net (loss)/income		2,091		(1,519)
Expenditure for long-term assets
Total assets		43,034				27,766
Intersegment Eliminations [Member]
Revenues
Cost of revenues
Total operating expenses
Depreciation and amortization expense included in total operating expenses
Operating loss
Change in fair value of warrant liabilities
Net (loss)/income
Expenditure for long-term assets
Total assets		(25,190)				(23,024)
Internet Ad [Member] | Operating Segments [Member]
Revenues		8,267		3,236
Cost of revenues		8,738		3,110
Total operating expenses		383		1,022
Depreciation and amortization expense included in total operating expenses		35		206
Operating loss		(854)		(896)
Change in fair value of warrant liabilities
Net (loss)/income		(954)		(893)
Expenditure for long-term assets		1,160
Total assets		11,186				8,310
Ecommerce O2O Ad and Marketing Services [Member] | Operating Segments [Member]
Revenues		129		503
Cost of revenues		375		375
Total operating expenses		203		4
Depreciation and amortization expense included in total operating expenses		75
Operating loss		(449)		124
Change in fair value of warrant liabilities
Net (loss)/income		(449)		103
Expenditure for long-term assets
Total assets		5,192				3,206
Blockchain Technology [Member] | Operating Segments [Member]
Revenues
Cost of revenues
Total operating expenses		1		1
Depreciation and amortization expense included in total operating expenses		1
Operating loss		(1)		(1)
Change in fair value of warrant liabilities
Net (loss)/income		(1)		(1)
Expenditure for long-term assets				$ 302
Total assets		4,405				$ 4,409
Corporate Segment [Member]
Revenues		8,396
Cost of revenues		9,113
Total operating expenses	[1]	1,098
Depreciation and amortization expense included in total operating expenses		112
Operating loss		(1,815)
Change in fair value of warrant liabilities		$ 2,507

[1] Including approximately US$0.10 million share-based compensation expenses.

[2] Including approximately US$1.92 million share-based compensation expenses.