Facebook says it has 845 million "monthly active users" and 483 million "daily active users," but there are concerns the company's estimates could be inflated. The network counts people who "like" content or cross-post content from other sites as active users, even though such users are of little interest to Facebook's advertisers, experts say. "I think most of us would say that the 'real number' of Facebook monthly active users are the folks who go to the Facebook website or mobile site. ... It would be interesting to know what percentage of 845 million people fits that simple definition," Eric Jackson writes.