An escort I saw frequently once told me that he knows he's a good looking guy and can walk into a bar and pick up pretty much anyone he finds attractive. But, he has a big dick and often he gets back to his place and the trick goes all "it's too big, it's going to hurt, whine, whine, whine. He said he loves to fuck and so he decided to put a picture of it on the internet, only guys who can take it call him and now he gets to fuck all he wants and gets paid too. Win, win - the birth of an escort.