Hi Daniel,
First, you need to check what’s the conversion point. That information is usually availabl in the offer’s description.
All offers will have a back-end, but what matters for the affiliate is where the conversion occurs.
In case the offer requires a 2nd page submit and more complex information such as a phone number, it doesn’t necessarily mean that it’s a bad offer. It can still be a great one, just the payout has to be proportional and you need to come up with an angle that hooks people and make the offer interesting for them.
WIlliam