I've always wondered if sites do this the other way around. A site invests a lot in content they create you would think to get the most out of it they would ser

I've always wondered if sites do this the other way around. A site invests a lot in content they create you would think to get the most out of it they would serve it with different headlines to different demographics. Knowing from Facebook what headlines you have clicked through in the past can indicate how they should write future headlines to get you again.