This was on Something Awful, and I assumed at first it was a gag ad. Oh, it's not.
EDIT: Concerning plentyoffish.com, I just figured out that it's supposed to be "Plenty of Fish", not "Plenty Offish". I assumed it referred to the physical attractiveness of those who would visit the site, "offish" being an adjective denoting homely looks. Of course, that seemed somewhat self-detrimental, but I supposed that was a gimmick of sorts.
EDIT 2:
This is what happens when you let the Sunday School class design your dating website's banner.