There are more than 400,000 merchants to do promotions or offer rewards or discounts to customers and about 10,000 developers writing third-party applications for the platform, he said, such as one that warns you if a restaurant where you've checked in has received a poor health inspection report.

The company is generating revenue -- he wouldn't say how much -- but is not yet focused on turning a profit, Crowley said.

Sharon Machlis is online managing editor at Computerworld. Her e-mail address is . You can follow her on Twitter , on or by subscribing to her RSS feeds: | .

in Computerworld's Web 2.0 and Web Apps Topic Center.