A 2013 study determined that ninety-five per cent of individuals could be positively identified based on just four locations they’d visited. “Just show me where your phone is between midnight and eight o’clock, and I’ve pretty much figured out who you are,” one veteran location-data analyst told me. “There’s no such thing as anonymized data,” the technology writer Clay Shirky, Crowley’s former professor at N.Y.U. and a mentor from his Dodgeball days, agreed. “There’s only useful and non-useful data.” At the moment, individualized data isn’t that useful to marketers. But that could easily change, especially for those peddling big-ticket items. Moreover, Foursquare’s user information is now its most desirable asset, and would be acquired by a third party if the company were sold.

Ariela Ross isn’t among them. Although she hasn’t used Foursquare for years, she told me recently that she didn’t mind sharing her own location with companies “if it makes my life better and more efficient.” Industry experts believe most of us will take the same view, if we haven’t already. “It’s happening,” Albert Wenger, a Foursquare board member, said.