The Guardian reports that dating site Ashley Madison (motto: "Life is short, have an affair") has placed the bounty on Clarkson's head in hopes that the Top Gear host will work as the site's public face. The Guardian feels Clarkson would be a lousy spokesperson for the site given the fact that his alleged affair was anything but discreet, but the site doesn't seem to feel that way.
An Ashley Madison spokesperson reportedly told the paper "what he has or hasn't allegedly done isn't important, he has made discreet adultery a major talking point." We'd add that if Ashley Madison were looking for a more discreet cheater that hasn't been caught, he or she certainly wouldn't be a spokesperson for the site... unless they wanted to be caught.
Further, we're guessing the £1 million offer has a lot more to do with the website trying to gain some publicity for itself, as the chances of Clarkson taking them up on the offer are slim to none. And for the record, Clarkson and his assistant both claim the alleged affair never happened.