Really, 300 tgp's? I don't think the common submitter's list of the biggest tgp's goes much above 100. Did you check the traffic rank of those tgp's before adding them to the list?
www.alexa.com I personaly don't submit to tgp with a traffic rank higher than ~120,000. Not worth my time and effort. I'm sure if you go through your list of sites you'll find a few with 1,000,000+ rank.
But anyways, that's just me
