Rank	Sport	Audience	Regions
1	Football (Soccer)	4 Billion	Europe, Africa, Asia, America
2	Cricket	2.5 Billion	Asia, Australia, UK
3	Basketball	2.5 Billion	America, Oceania, Middle East
4	Field Hockey	2.2 Billion	Europe, Africa, Asia, Australia
5	Tennis	1 Billion	Europe, Asia, America
6	Volleyball	900 Million	Europe, Australia, Asia, America
7	Table Tennis	850 Million	Europe, Africa, Asia, America
8	Baseball	500 Million	America, Japan
9	Rugby	475 Million	Oceania, South Africa, England
10	Golf	450 Million	America, Oceania, Europe

 Well since we were talking about it I decided to do some (limited) research.  Some of the stats seemed outdated as basketball has really taken off these last few years so this table is only an approximation based on numbers I was able to find online. The popularity of Field Hockey blew my mind.