there is a lot of features that are a must for a GPT script.
examples
the compete offer notice MUST appear live in the shout box, failure to have that will destroy any GPT site from ever becoming popular.
Ones balance on every page (some sites do not do this and it becomes a headache to figure out if the survey you just did even credited)
Plus it must be very well organized requiring very little mouse clicks to get to the surveys.
NO CAPTCHA in the sign in page, any site that does not do the above things with their script will fail.
No one will bother with a site that does not show the surveys being completed in the shout box, and having to keep refreshing the page and/or click out of the survey to then get to ones balance, to figure out if the survey credited or not, so they can clear cookies and begin a new one.
Plus no one will stick around a site that requires captcha when signing in
Preferably, 3 areas at the top, showing most completed, recently completed and recently added surveys.
As well as the sites over all pay out, clearly for everyone to see, even those not signed in along with all the sites stats.
ways to add customized contests, such as, daily, monthly, or anything the admin wishes, such as "for every 10 offers completed you will receive an additional 10 points" "for every two dollars made, you will receive an extra 50 cents" etc.