"WarBook," a role-playing game with no animated graphics, and other Webs.com games have generated a billion page views since the first game launched in August. They're generating ad revenue with every view, since there are ads on each screen of the game. "WarBook," a kind of tic-tac-toe for Facebook, is part of what Webs.com is calling its Social Gaming Network (www.socialgn.com).

The game usage numbers are astounding. But they are not surprising, given the velocity of Facebook's growth and the viral appeal of hot applications on its platform. The page-view numbers - which many companies with big budgets and huge development teams would love to have - give you an idea of why some folks feel that Facebook deserves its valuation of $15 billion. And while "WarBook" is wildly popular, it's not even the most popular application on Facebook. It's just one example of many popular applications on the social networking site.

Shervin Pishevar, president of Webs.com in Silver Spring, Md., says the company's handful of games launched so far are exclusively aimed at social networks such as Facebook or MySpace.

"We launched it and it's exploding," Pishevar said. "'WarBook' is getting 15 million page views a day."

This shows how game developers can ride the bandwagon of Facebook, which is gaining millions of members a week. But the big winners so far are not the traditional casual or ad-supported games that companies such as Electronic Arts create.

For instance, "Street Race" is a new free SGN game that has no animated graphics. You simply sign up, get $1,000 in play money, buy a car with virtual money, then race. To race, you click on another user. Then nothing happens, not even an animation of the race. The next screen that comes up tells you if you won or lost, how much money you earned or lost, and the skill points you earned. As your skill points grow, you win more races and get more money to spend souping up your car. The social part comes in where you can get more money by inviting 20 friends to join.

Facebook makes it simple and easy for developers to launch new applications. A year ago, it began publishing the programming information that third-party software developers needed to create applications that run on its platform. With tens of millions of new users, Facebook's audience is ripe for new applications - allowing "Street Race" to garner more than a million page views on its first day. You can play a round in about one second. Such simple games are a lot less time consuming than even the "casual" games that appear on other types of social game networks, such as www.kongregate.com or www.bigfishgames.com.

Games such as "Street Race" are ideally suited to an application like Facebook, which people use for a short time each day. Facebook benefits because it gets users to spend a lot more time inside the Facebook universe. SGN gets revenue from ads that run on the pages with the games.