Twitter says that in most instances it only counts the revenue from a deal after the services have been delivered and the company knows how much it will get paid. But it says in some more complicated deals, it resorts to estimating what it might get paid. It's not clear how often it relies on projections.
Michael Pachter, an analyst at Wedbush Morgan who follows social media companies, guesses Twitter only estimates revenue in long-term advertising deals. And Pachter says he doesn't believe the company has many of those yet.
"I don't think it's a big deal," says Pachter. "But it is something the company will be questioned about."