Fast forward to 2013, UltimatePoker.com went live in April, becoming the first legal, real-money poker site in the U.S. "You can register and deposit from anywhere, but you can only play [online] from within the state of Nevada," Tom Breitling, chairman and co-founder of Ultimate Poker told CNBC.
"It's pretty exciting that there's economic development happening with jobs and taxes," he added. "We have over a hundred employees. We're hiring new people every day, especially as this looks to expand beyond Nevada."
New Jersey, which has approved "full-blown casino gaming" legislation, is the next state on the company's list for expansion, he said. "Then you have Deleware that's also approved it. And there's about 10 other states that are looking at it and are very serious about the legislation."
(Read More: New Jersey Gets Online Gambling as Governor Signs Revised Bill)
Breitling is no stranger to gambling.
After selling online travel company Travelscape.com to Expedia for more than $100 million, Breitling and his business partner in 2004 bought The Golden Nugget for $215 million. They had become the youngest casino owners in Nevada. About a year later, they sold The Golden Nugget to Landry's Restaurants for around $340 million.
The most important decision Ultimate Poker made as a company was to own its technology, Breitling said, explaining the process for screening users to make sure "they are who they say they are," at least 21 years old, and in the state of Nevada.
"It's really complex technology that verifies your IP address. No [virtual private networks]," he added. "And you have to have a cellphone. So we ping you with a cellphone to make sure you're within the state. And we send you a text message, and you have to reply to that."
As Ultimate Poker carves out its online platform, Breitling stressed that he's cognizant of the potential for cannibalizing the business of physical casinos. "Our partners, Frank and Lorenzo Fertitta, own Station Casinos and they are also the owners of the Ultimate Fighting Championship."
"We're going to do nothing that jeopardizes that land-based operation [in Vegas]," Breitling pledged. "For us it's about this integrated online/offline relationship."
(Read More: Caesars Plans to Launch Online Poker This Summer in Nevada)
Gaming revenue from the Vegas strip totaled $6.2 billion last year, according to the Las Vegas Convention and Visitors Authority. In the years to come, legalized online gaming in the U.S., by many estimates, could approach $10 billion annually.
It only makes sense to regulate and tax online gaming in the U.S. because it's legal in many countries all over the world, the "Straight Flush" author Mezrich argued. "The countries make a lot of money on it."
He pointed out that "a few weeks ago, we were all lining up for Powerball tickets" when the jackpot was more than a half billion dollars. "That's fine, but online poker is not fine? Where is the logic there."
—By CNBC's Matthew J. Belvedere. Follow him on Twitter