Welcome to WebmasterWorld Guest from 22.214.171.124
Certain programs like that do work, but it's not for everyone. I've had advertisers try to buy them from me, and I think there are actually networks that speciallize in them. I think they were paying $0.05 an email to publishers for 'entertainment' type sites.
If you're going to go this route expect a lot of fraudulent sign-ups and keep a close check on the merchants running it.