[jonlucc]

I suspect this is due to a firewall between the types of content. I don't remember what interview I was listening to years ago, but I think it was Matt Cutts who said that Google has a whole porn team that makes sure that when you want porn, you get the most relevant porn sites and when you don't want porn, you get none.

I think Reddit is in the same boat. People don't avoid Google ads because they might end up on porn; in fact, lots of products only want to be placed next to porn.