Yes the algorithm had changed aswell as the rise of facebook is 1 reason as people are shifting to it now
Yeah, I remember that back in 2008. One of our sites also dropped sharply. But I'm sure that there are sites that went up to fill up the gap vacated by our site and other sites that sank.
may be now people are going to facebook and myspace instead of orkut, orkut is mostly used in India n Brazil. so may be they are no more interested in orkut as they were in last year
I don't think Orkut's graph could go down like this, but the main reason is that Facebook is providing more and better security than orkut so people are shifting to Facebook.
Check out orkut.co.in's rank and orkut.com.br All Indian traffic is redirected to .co.in, and Brazilian to com.br and that's where most of the traffic to orkut.com came from.
Yep qprojects has provided the perfect explanation. If you sum up the traffic to different ccTLD's the graph would certainly be depicting an increased trend as you can see here