As I had noticed it depends on which country you are, just like basketball and boxing which are very well known in the country of the Philippines and in the US. So, I guess these sports might be triggered to them to join in sport betting those who passionate to watch the sport and bet as well. In some places like India, Pakistan and Sri Lanka they like also cricket and football game. So, at this point, we can measure which countries that has a lot of population and supporters in those kinds of sport betting games online.
I had quick researched and I found these.
You got it right! I agree that our preference on which sport that has many gambling supporters depends on the country where you are living. Like in my case, I'm living in the Philippines and the people here, especially the younger generation are all into basketball. In every place you visit here, you will see basketball courts or even a simple basketball ring attached on a wall and lots of children playing.
Filipinos are so fond of watching basketball games and make it an opportunity to conduct betting games on which teams who will win. Almost all Filipinos know what that is and how it is played.
Aside from basketball, boxing is popular here in the Philippines, too, because of Manny Pacquiao. Whenever Pacquiao has a fight, expect that there will be lots of people who will bet on him, even those who are not really into gambling, just to show how much he or she supported our people's champ.