Affiliate Marketing Secrets

I’m an affiliate with a website that offers hundreds of email/zip/address offers, where when I send a user to the link, I will get paid $X.XX if they simply enter their email/zip/address. I don’t know exactly what happens after of what the company does with their info, but I know all offers say Details Apply.
My question is, if I promote this offline with flyers, would it be legal? Are these things considered legal? I figure they wouldn’t be floating around the web if they weren’t and they probably found some legal loop-hole. Just wanted to make sure it was legal before promoting it offline.