A pair of Italian security researchers investigating the practice of Facebook scamming estimates that the trade brings in around $200m a year.
Andrea Stroppa and Carlo De Micheli analyzed the pricing of Facebook spam on 20 black-market websites offering access to Facebook users for a price. The spammers set up fan sites and encourage people to join them, then pump out spam messages to encourage click-throughs, bringing in between $87m and $390m per year.
"The spam posters get paid an average of $13 per post, for pages that have around 30,000 fans, up to an average of $58 to post on pages with more than 100,000 fans," De Micheli
told The Guardian.
