“Everyone is really anticipating this becoming a huge business,” said Chris DeWolfe, a co-founder of the pioneering social site Myspace, who is throwing his energies into a gaming studio with a gambling component backed by, among others, the personal investment funds of Jeff Bezos, Amazon’s founder, and Eric E. Schmidt, Google’s executive chairman.

As companies eagerly wait for the American market to open up, they are introducing betting games in Britain, where Apple has tweaked the iPhone software to accommodate them. Facebook began allowing online gambling for British users last summer with Jackpotjoy, a bingo site; deals with other developers followed in December and this month.

Zynga, the company that developed FarmVille, Mafia Wars, Words With Friends and many other popular casual games, is advertising the imminent release of its first betting games in Britain. “All your favorite Zynga game characters will be there, except this time they’ll have real money prizes to offer you,” an ad says. “Play online casino games for pennies and live the dream!”

Mr. DeWolfe’s studio, SGN, is also on the verge of starting its first real-money games in Britain. “Those companies that have a critical mass of users that are interested in playing real-money games are going to be incredibly valuable,” he said.

Mark Pincus, the chief executive of Zynga, said the company was just following the market. “There is no question there is great interest from all kinds of people in games of chance, whether it is for real money or virtual rewards,” he said. Zynga, which has missed revenue expectations in the last year, is making gambling a centerpiece of its new strategy. It has just applied to Nevada for a gambling license.

Casual gaming first blossomed on Facebook’s Web site, where players could readily corral friends into their games. It is now being rethought for mobile devices, so people can play in brief snippets as they wait for a bus or a sandwich.