Note 22 - Segment Reporting - Summary of Segment Reporting Information (Details) - USD ($) $ in Thousands	3 Months Ended						6 Months Ended
	Jun. 30, 2020		Mar. 31, 2020	Jun. 30, 2019		Mar. 31, 2019	Jun. 30, 2020		Jun. 30, 2019		Dec. 31, 2019
Revenues	$ 10,416			$ 15,453			$ 14,800		$ 24,020
Cost of revenues	10,118			15,087			13,603		23,212
Total operating expenses	1,318			1,588			4,493		2,768
Depreciation and amortization expense included in total operating expenses	208			14			415		52
Operating (loss)/income	(1,020)			(1,222)			(3,296)		(1,960)
Change in fair value of warrant liabilities	22			821			68		471
Expenditure for long-term assets							302
Net (loss)/income	(970)		$ (2,310)	(382)		$ (1,140)	(3,280)		(1,522)
Total assets	17,074						17,074				$ 18,551
Corporate, Non-Segment [Member]
Revenues							645
Cost of revenues
Total operating expenses	380	[1]		419	[2]		2,528	[3]	871	[4]
Depreciation and amortization expense included in total operating expenses	1			1			2		16
Operating (loss)/income	(380)			(419)			(1,883)		(871)
Change in fair value of warrant liabilities	22			821			68		471
Expenditure for long-term assets
Net (loss)/income	(311)			401			(1,830)		(400)
Total assets	21,659						21,659				21,338
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	(21,885)						(21,885)				(22,079)
Internet Ad [Member] | Operating Segments [Member]
Revenues	9,912			15,453			13,148		24,020
Cost of revenues	9,743			15,087			12,853		23,212
Total operating expenses	930			1,145			1,952		1,850
Depreciation and amortization expense included in total operating expenses	206			12			412		35
Operating (loss)/income	(761)			(779)			(1,657)		(1,042)
Change in fair value of warrant liabilities
Expenditure for long-term assets
Net (loss)/income	(757)			(760)			(1,650)		(1,075)
Total assets	10,656						10,656				13,332
Ecommerce O2O Ad and Marketing Services [Member] | Operating Segments [Member]
Revenues	504						1,007
Cost of revenues	375						750
Total operating expenses	5			18			9		36
Depreciation and amortization expense included in total operating expenses
Operating (loss)/income	124			(18)			248		(36)
Change in fair value of warrant liabilities
Expenditure for long-term assets
Net (loss)/income	101			(17)			204		(36)
Total assets	2,464						2,464				2,075
Blockchain Technology [Member] | Operating Segments [Member]
Revenues
Cost of revenues
Total operating expenses	3			6			4		11
Depreciation and amortization expense included in total operating expenses	1			1			1		1
Operating (loss)/income	(3)			(6)			(4)		(11)
Change in fair value of warrant liabilities
Expenditure for long-term assets							302
Net (loss)/income	(3)			$ (6)			(4)		$ (11)
Total assets	$ 4,180						$ 4,180				$ 3,885

[1] Including approximately US$68 thousands share-based compensation expenses.

[2] Including approximately US$102 thousands share-based compensation expenses.

[3] Including approximately US$1,987 thousands share-based compensation expenses.

[4] Including approximately US$203 thousands share-based compensation expenses.