The metrics are just for papers uploaded to Academia.edu (as stated in my previous commment). I think real time metrics will come to other research sharing platforms. Academia.edu is leading the way here.

I would question your assumption that academics have not heard of Academia.edu. 1.7 million academics have signed up, and around 3,500 join each day. It's one of the largest research sharing platforms on the web, with more than ten times the traffic of, say, ArXiv.