Pinterest, the social image-sharing pinboard site beloved by maiden aunts and chronically depressed  ex-girlfriends everywhere,  isn't so hot anymore,  apparently. While Pinterest soared in popularity at the end of 2011 and by March this year was the third most popular U.S. social network, new user signups appear to have dropped off a cliff. Nicholas Carlson made note of this in Business Insider several days ago:

Most Pinterest users sign-up to the site using their Facebook accounts, and AppData, which monitors how often users of third-party apps and Web sites interact with Facebook, says the number of Facebook-connected Pinterest users has declined precipitously the past 50 days.

This may not really be a problem for Pinterest in the end, simply a symptom of the site's huge upswing in popularity--a natural correction. As Mr. Carlson noted, January through March of 2012 has seen a huge burst in overall interest in the site, with Google searches steadily increasing as Pinterest's mass of new users gave the site a shot over the last 2 months or so.