Originally Posted by
Chopsticks
Do you mean biggest = most members or most turnover? There may be a big difference here as maybe the typical Ladbrokes customer may be a westerner with a job or some kind of income, but maybe the typical sbo customer is a vietnamese guy working in a rice field (exaggeration to make a point) who occationally places $1 bets.. I know Ladbrokes claims to have 800.000 "active" customers so they probably have 5 times that in total.. And that is not counting all the betting shop activity.
I am not sure if SBO and those are much bigger... Ladbrokes is well-known all over the globe and spend a good amount of money to market themselves.
There are turnover reports available for many of the bookies online, I found the bet365 one for 2010 pretty quickly and they say £1.8 Bn which I would guess is about $3bn.