How horny are Tumblr users?
 

They're very horny. "the researchers note that self-reported demographic data suggests the user base of Tumblr is largely young and female [...]" Interesting.

Well there is a lot of horny wankers on the Tumblr. The site can bring a good traffic to an adult site.

I always love seeing my porn next to feelgood ads...

The same would work for Reddit/Twitter/Facebook user