Honestly girl i wouldnt worry about it, no site can guarantee an offers crediblity unless they tried each an every offer themselves, an no matter what forum u ever go to on one of these types of sites, someone is always talkin about how they got scammed, or almost got scammed. Those offers usually get away with their behavior by using certain terms most folks wont catch or pay attention to...one i can think of right off is..instead of saying you got '30 days' to try something out...they say you got '4 weeks'...and trust me..its not the same!
Some offers i imagine will be shady, this is the internet after all...I learned the hard way from another site..to read... READ, those TERMS very carefully, cuz if you dont, and u got a credit card on the line...being negligent can an WILL come back to haunt you....When i almost got scammed, it wasnt like there was anyone i could run an tell, -cept for my bank-...but I was not happy when i saw that same offer being featured on what used to be my favorite GPT site...i did tell them about the offer, even sent them the link to ripoff report.com so they could actually READ for themselves what those folks had done to me and others,...but the offer is still there..so i clearly wasted my time...-shrug-...i will just watch their forums fill up with complaints i spose..
As for those 'metal' offers, i dont think most folks bother with all that..i just keep clickin...an hope for credit...heck some sites are now tellin their members all they have to do is the first 3 or 4 pages of those an they will get credit...