I get Russian, Chinese, Latina and Black dating sites though, which is odd as I'm not dating and have never used a dating site (I'm with the same lady for 17 years and I behave myself)
I assumed most ads were targeted by your browser history
As mrmojo said, the RV and trailer ad pops up a lot but I have been browsing a lot of RV models recently...my neighbor got one and now I'm all into them so the RV ad makes sense...