Hmmm Doctor, many of the submitters here can't use your tgp. 'Only two sponsor banners allowed' (Freehosts INCLUDED) is your wording so only a very few freehost gals could be posted to your site.
You might mention that when you are telling them your hit rate to get them to come submit. It's wasting their time if you don't.
Why not just ban all freehosts and be done with it?