[Analyst]

I'll have to think about this model but can give some guidance as to the number of players (N).

PokerStars announced their five millionth player in March 2006. Pre-UIGEA, Party was substantially larger; between the two sites it could have been around ten to twelve million (there would be a great deal of overlap, of course). Accounting for unique players at other sites, new signups, etc., off the top of my head I'd probably put today's number at 15-20,000,000.

Note that this includes both real and play money players. If you limit this to only people who have played for real money, the number is a lot smaller.