Earlier quoted context omitted.
One, you presume that advertisers are incredibly naive and don't measure returns. Obviously cleanly measuring advertising returns from fb is hard, but it's still being done. Second, fb can put up the first credible alternative to adsense since they collect browsing info from their fb login and other widgets. In fact, they can do better than adsense: fb can mix in very accurate demographics alongside the page context.…
http://www.forbes.com/sites/ryanholiday/2012/05/17/why-i-los... Advertising isn't worthless, but advertisers are very naive. You talk about companies spending money because they are stupid. I SUSPECT, but only Facebook has the data to KNOW, that there is a high turnover in companies advertising on Facebook. New companies coming in every day, but also many who realize they aren't getting a return on investment and lea…
Also -- ctr doesn't matter as long as your cpc compares. So 1/100 the ctr is fine w/ 1/100 the price, etc.