Recently, the Poker Players Research (PPR) did a study on various online poker markets and concluded that, to date, the US is the largest in the world.
What seemed surprising about this is the fact that the US government passed the UIGEA in 2006 and, ever since, poker in the country became a delicate issue. However, the study says there are still more than 10 million American real money players willing to gamble at the virtual tables.
The UK was the runner-up with 1.9 million real money players. As you can see the difference is huge even though there are less poker rooms willing to provide services to American poker players.
Actually, the few poker rooms that still work for US players, like
Pokerstars and Full Tilt, have managed to amass what adds up to more than half of the online poker market share. I can't even imagine how much the figures would rise if the ban on online poker is lifted in the near future.
These were the results of the study, hence the five biggest online poker markets:
USA -10 million real money players
UK -1.9 million real money players
Germany -1.6 million real money players
Nordic countries -1.4 million real money players
France 1.3 million real money players