In many ways, it seems the story of online dating sites should tell itself.

"When you build an app that allows you to have an affair anywhere because it locates people who want to have an affair by GPS, that's probably a story the media will be interested in," says Noel Biderman, CEO and founder of AshleyMadison.com, the dating website that caters to people who are already in a relationship, but looking to have an affair or cheat. ...