Pump.io is the successor of identi.ca. It’s an open source alternative to twitter.
About 4k visitors a week. Not bad for a relatively new website, hey?
Except that identi.ca had at least 40k weekly visitors, possibly even more. And even now it still seems to get ~9k visitors every week.
And that’s quite a lot considering that no one can really post anything new on identi.ca. I really wonder why this “upgrade” has not been handled in a smoother way that would have retained existing users. Backwards API compatibility would have meant composer and a couple of other social networking tools would have supported pump.io.