Where's the beef?
What makes any of this worth anything?
I guess it's because Facebook can exploit that data to compel a certain portion of the population to buy something or other, for which Facebook demands a commission.
(Sorry, I remember there was some question from the 'social network' movie which was: what exactly is the value of Facebook, what is it that makes it a business - and I guess ultimately this is what it is? I'm actually not sure.)