I tell you, Baudrillard would have a blast with a phenomenon as oxymoronic as "reality television."
I really think it comes down to a voyeuristic impulse. I mean, how many people gossip, even though it serves no useful purpose? Everybody wants to know what's going on with everybody else, so that they can draw their own conclusions (tainted by hearsay, of course). But with reality TV, you get the satisfaction of gossip, and the implied superiority of the viewer over the subject. That's what real voyeurism is: deriving pleasure from observing someone who has no power over your gaze. In real life, if you watch two strangers making out intently, they'll probably tell you get lost. On television, you can watch and they can do nothing about it. It's like the Ring of Gyges in real life.
When a person watches a show like "Cheaters", they get to experience "drama without drama", and a chance to judge complete strangers with no strings attached. How hard can it be to feel good about yourself when you have plenty of "real" people to look down upon on television?
A lot of people dismiss the appeal of reality television as that of people whose "real lives" simply aren't interesting enough. On the contrary, I'd say that it's not a result of one's personal life being uninteresting, but the result of there being a certain power in reality television that's lacking in real life.