For Bump Technologies, 3 million is a more significant number than 1 billion. The company that famously developed what was the 1 billionth iPhone application downloaded from Apple reportedly raised more than $3 million in its first institutional round of financing.

Smooth move for a company that doesn’t even charge a penny for its primary social networking service. Founded a year ago by then-University of Chicago business students David Lieb and Jake Mintz, Bump enables those who download the application to share contact information with one another simply by tapping their iPhones together. Earlier this year, the company moved to Mountain View, Calif., in part for greater access to venture capital.

The ascent of mobile applications, including those developed for the BlackBerry and Google’s Android operating system, resembles the early days of the World Wide Web about a dozen years ago. One big difference is that more people own cell phones than they do computers. ”You are probably talking about five or 10 times the number of users,” explains Steven Kaplan, the acclaimed professor of entrepreneurship and finance at the University of Chicago’s Booth School of Business.