chicagohh - 5:41 pm on Aug 2, 2012 (gmt 0)
I think 8.7% is low. It's laughably easy to fake social signals. People want to be liked and most people find it hard to offend others... this means that for the cost of a yahoo email and a few hours anyone can build a FB profile with 100 friends. If you do this off and on over a few months it's not hard to have 50 hand built FB accounts with people you don't know responding to your updates or wishing you a happy birthday.
Twitter is even easier.
Mind you - this is all done by hand. There are programs that do this in bulk.
8% - LOL!