Twitter has stopped displaying what the site’s power users call “@replies” — messages broadcast in public, but directed at a specific user — when the viewer doesn’t also follow the message’s target. Twitter users will still see conversations, but only when they happen entirely within their social circle.

You can no longer easily eavesdrop on conversations with strangers. Hurrah!

Technically, Twitter has stopped displaying what the site’s power users call “@replies” — messages broadcast in public, but directed at a specific user — when the viewer doesn’t also follow the message’s target. Twitter users will still see conversations, but only when they happen entirely within their social circle.

For the attention-deficited social butterflies of Silicon Valley, this is a horrible development: They can no longer ignore their existing friends in favor of constantly finding new ones.

But for the mass market Twitter hopes to tap, this is a great thing. New users find Twitter overwhelming and confusing; some 60 percent drop out after signing up, according to Nielsen, which means Twitter is proving far less capable of retaining an audience than Facebook or MySpace. These Twitter quitters mean that Twitter’s growth lies on the edge of a knife. While its traffic numbers are growing at an unheard-of pace, it could lose its audience all too easily. Rest at ValleyWag