"Remove the few rich guys and Farcebook will lose most of its income"
Do you believe rich people buy a house, car or a boat because they've seen it on Facebook? LOL!
Facebook & C. are probably far more useful to address middle and low income people, because first, there are more, and second, companies fight far more to get whatever share of their income (or debts..) they can spend.
It's like TV, how much is made to appeal to the upper echelon of a society, and how much for the lower one - including ads? There's also a far bigger chance those people will spend more time on FB or watching TV, than people with far more money who can spend their time in many other ways.