But the truth of the matter is the Texas Hold'em Poker application built by Zynga has over 15 million monthly users, dwarfing dedicated online poker rooms like PokerStars and Full Tilt.
Even the creators of the game are impressed by its success.
"Texas Hold'Em is Zynga's #1 game," said Sam Singh, Zynga's GM of Casino Games. "It's constantly in the top 5 games on Facebook and MySpace. We continue to be amazed by how successful it has been."
Texas Hold'em was also Zynga's first game and the one that turned the once fledgling social gaming company, fronted by Mark Pincus, into an online gaming powerhouse that earns more than $100 million a year.
It was no mistake that the game driving Zynga to the top has a key social element involved.
"Poker is a universal game, played by millions of people," explained Singh. "The inspiration of our application was to make 'Poker Night' with your friends, a regular event no matter what your geographic location."
This year, for the first time ever, Facebook Poker players made the public transition to live real-money poker thanks to a cross promotion between Zynga and the World Series of Poker.
Two lucky winners got the chance to play in the 2009 WSOP Main Event and one of them made it as far as Day 3 of the prestigious event.
According to Singh, it's only a matter of time before players weaned on Facebook begin to make waves in live poker.
"Our poker game is the biggest on the planet, so I assume that at some point we'll see a champion emerge that sharpened his chops on our game," he said. "One of our finalists made it to [Day] 3 so I'm hoping next time we'll see one of our Zynga Texas Hold'em winners emerge as the winner in one of these real-world tournaments."
Poker's boom began in 2003 when Chris Moneymaker took down the WSOP Main Event after winning his way into the tournament through a $39 PokerStars satellite.
Respected British poker journalist Shelley Rubenstein said a Main Event winner coming from Facebook could possibly be the catalyst for a similar boom.
"I think it would help open poker up to a whole new audience," she said. "A whole new demographic that would otherwise have no interest in the game."
Elite online poker player Carter "ckingusc" King, who won the PokerStars WCOOP Main Event in 2008 for $1.3 million, also believes the popularity of poker on Facebook is a positive development for the industry.
"I have a ton of friends who enjoy playing on there so much that they come to me and ask about playing on the major sites," King said. "Anything that encourages more people to play the game is great."