"Whenever I hear SMB, I think of Super Mario Bros," Foursquare co-Founder and CEO Dennis Crowley said today. But in all seriousness, he has tremendous pride in his service and its future use for local businesses (among other things). Speaking here at ad:tech New York, he compared Foursquare to a Google Analytics for people who walk in your door. "These are your best customers," he said. "The check-in is kind of a commodity."