As an experiment, Cracked writer Alli Reed composed a fictitious but truly awful online dating profile. Her goal was to to create a persona that was truly despicable and that no one would ever consider dating:
In making this profile, I made sure my creation touched on every major facet of being truly horrible: mean, spoiled, lazy, racist, manipulative, and willfully ignorant, and I threw in a little gold digging just for funzies. I maintain that there is not a human on this planet who would read this profile and think, "Yes, I'd like to spend any amount of the fleeting time I'm given on my journey around the sun getting to know this person."
As you can see, she put a lot of thought into how truly offensive she could be. Her persona, aaroncarterfan, is despicable. She openly brags of engaging in paternity fraud and harassing homeless people.
But within a day, she received 150 responses from interested men. In their online conversations, she did her best to convey the impression that aaroncarterfan would be the worst possible girlfriend. She was unsuccessful. You can read them here.
No, I've never posted on a dating site. I looked at one when I was single, and when I narrowed it to local guys, I found I knew most of them already. And their ex-wives.