I was obviously wrong then. AFAIK, the biggest bookies in the world(Laddies, Willhill, Coral etc) have a hard time breaking the 200 million pounds bareer on an year's net revenue and that is including Casino games and FOBT's. Betfair is @ 210 USD from what I last heard, so your assumtion was more than correct, in which case a 12 billion digit sounds not only wrong but flatout ridiculous. If the big 5 can hardly make for 1 billion(and let's assume Party Poker ads for another billion...), there is no way in hell the rest of the industry sums up to 10 more. I'd agree with you, the number is ridiculous in that case.
Edit: Going to bed, will check some numbers and come back tomorrow...