Have you tried actually logging in? This is not quite arxiv.org — I'd estimate that 90% of the engineering going into academia.edu has gone towards features on par with LinkedIn for their spamminess. I signed up, and was asked about 10 times to connect to Facebook, Gmail, invite my friends, etc.
They have some interesting features (such as feeds of recent articles organized by journal you can sign up for), but by far the most important feature of academia.edu is growing academia.edu.
They have some interesting features (such as feeds of recent articles organized by journal you can sign up for), but by far the most important feature of academia.edu is growing academia.edu.