I am thinking about running a email submit, but I want to see how other people run them. Should I use an I-Frame or just a regular landing then to the offer?

Simple LP sales page would be a good test.

Your best bet is just to see just that, see how other people are doing them by clicking on their text advertisements.

I run a few zips on content that actually do very well along on search.

I use a simple landing page, very professional looking. Of course, it's not like a Free iPhone offer or anything, the offer is targeted towards middle aged people and not offer expensive "free" items.

I experience nothing below 70% conversion rate for my offers, along with others in the past I have ran.