Who knows what the software is collecting and sending back to base?
One supermarket around here (in order to avoid lawsuits let's call it Carrefive) used to had an interesting system to get customers to join their credit card program: when you paid at the cashier they ask if you were going to pay with the Carrefive card. When you answered cash or another credit card somehow they would summon a lady who would try, very insistently, to make you join their card program.
After this happening to me five, six times in a row, I've asked them to stop it, not because it was annoying but because it was pointless since they tried several times in a short interval and I wasn't interested. I guess they stopped because I was polite and smiling all the time while explaining that it was annoying.
Back to Facebook: maybe they're monitoring you because you have a cell phone and is not a Facebook user? Some marketers are probably scratching their heads thinking about what to do. They'll send the goons soon.