I am not sure of the exact program you are talking about but those are usually co-registrations where a user signs up for a newsletter, etc, and at the bottom are a bunch of checkboxes (pre-checked) that sign you up for other newsletters.
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.
A couple of years ago we ran an affiliate scheme paying for sign-ups to a UK student site. Unfortunately pretty much all the sign-ups were fraudulent coming from the site owners of generally russian 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.