Note 22 - Segment Reporting - Summary of Segment Reporting Information (Details) - USD ($) $ in Thousands		3 Months Ended			6 Months Ended		9 Months Ended
		Sep. 30, 2020	Sep. 30, 2019		Jun. 30, 2020	Jun. 30, 2019	Sep. 30, 2020		Sep. 30, 2019	Dec. 31, 2019
Revenues		$ 12,304	$ 15,508				$ 27,104		$ 39,528
Cost of revenues		12,945	14,616				26,548		37,828
Total operating expenses		763	1,167				5,256		3,935
Depreciation and amortization expense included in total operating expenses		207	14				622		66
Operating (loss)/income		(1,404)	(275)				(4,700)		(2,235)
Change in fair value of warrant liabilities		(64)	(120)				4		351
Expenditure for long-term assets			760				302		760
Net (loss)/income		(1,333)	(391)		$ (3,280)	$ (1,522)	(4,613)		(1,913)
Total assets		17,010					17,010			$ 18,551
Operating loss		(1,404)	(275)				(4,700)		(2,235)
Net loss		(1,333)	(391)		$ (3,280)	$ (1,522)	(4,613)		(1,913)
Expenditure for long-term assets			760				302		760
Corporate, Non-Segment [Member]
Revenues
Cost of revenues
Total operating expenses	[1]								1,350
Depreciation and amortization expense included in total operating expenses									17
Operating (loss)/income									(1,350)
Change in fair value of warrant liabilities									351
Expenditure for long-term assets
Net (loss)/income									(999)
Operating loss									(1,350)
Net loss									(999)
Expenditure for long-term assets
Intersegment Eliminations [Member]
Revenues
Cost of revenues
Total operating expenses
Depreciation and amortization expense included in total operating expenses
Operating (loss)/income
Change in fair value of warrant liabilities
Expenditure for long-term assets
Net (loss)/income
Total assets		(21,330)					(21,330)			(22,079)
Operating loss
Net loss
Expenditure for long-term assets
Internet Ad [Member] | Operating Segments [Member]
Revenues		11,435	15,508				24,583		39,528
Cost of revenues		11,994	14,616				24,847		37,828
Total operating expenses		409	675				2,361		2,525
Depreciation and amortization expense included in total operating expenses		205	12				617		47
Operating (loss)/income		(968)	217				(2,625)		(825)
Change in fair value of warrant liabilities
Expenditure for long-term assets			760						760
Net (loss)/income		(893)	221				(2,543)		(854)
Total assets		10,830					10,830			13,332
Operating loss		(968)	217				(2,625)		(825)
Net loss		(893)	221				(2,543)		(854)
Expenditure for long-term assets			760						760
Ecommerce O2O Ad and Marketing Services [Member] | Operating Segments [Member]
Revenues		269					1,276
Cost of revenues		375					1,125
Total operating expenses		6	6				15		42
Depreciation and amortization expense included in total operating expenses
Operating (loss)/income		(112)	(6)				136		(42)
Change in fair value of warrant liabilities
Expenditure for long-term assets
Net (loss)/income		(94)	(6)				110		(42)
Total assets		2,093					2,093			2,075
Operating loss		(112)	(6)				136		(42)
Net loss		(94)	(6)				110		(42)
Expenditure for long-term assets
Blockchain Technology [Member] | Operating Segments [Member]
Revenues
Cost of revenues
Total operating expenses		1	7				5		18
Depreciation and amortization expense included in total operating expenses		1	1				2		2
Operating (loss)/income		(1)	(7)				(5)		(18)
Change in fair value of warrant liabilities
Expenditure for long-term assets							302
Net (loss)/income		(1)	(7)				(5)		(18)
Total assets		4,193					4,193			3,885
Operating loss		(1)	(7)				(5)		(18)
Net loss		(1)	(7)				(5)		(18)
Expenditure for long-term assets							302
Corporate Segment [Member]
Revenues		600					1,245
Cost of revenues		576					576
Total operating expenses		347	479	[2]			2,875	[3]
Depreciation and amortization expense included in total operating expenses		1	1				3
Operating (loss)/income		(323)	(479)				(2,206)
Change in fair value of warrant liabilities		(64)	(120)				4
Expenditure for long-term assets
Net (loss)/income		(345)	(599)				(2,175)
Total assets		21,224					21,224			$ 21,338
Operating loss		(323)	(479)				(2,206)
Net loss		$ (345)	(599)				(2,175)
Expenditure for long-term assets

[1] Including approximately US$307 thousands share-based compensation expenses.

[2] Including approximately US$104 thousands share-based compensation expenses.

[3] Including approximately US$2,066 thousands share-based compensation expenses.