Panthro - 7:13 pm on Sep 12, 2012 (gmt 0)
I don't think it's as much as what people intend to do on facebook and how they are not in 'buy-mode'.... but what they do afterwards and how they get there.
1. Log into Facebook
2. Waste time
3. Enough time wasted... possibly search for something?
Guess this is why they started displaying those ads on logout.