There are cheaters in every type of business, but for Ashley Madison, cheating is business.

Ashley Madison is a dating site marketed specifically at people who are already in relationships. Millions of people subscribe and pay to use Ashley Madison to find potential affairs.

And business is good, even if it’s widely considered immoral.

So how do you start a company centered on cheating? And how do you sell something that repulses so many consumers?

Noel Biderman, the founder and CEO of Avid Life Media, which owns Ashley Madison, joined Marketplace Weekend to explain the business of cheating.