Now that I have my first TGP up and running, I am running into the same probelm on getting traffic going as well. I have purchased traffic to roll in, signed up with a few trades that have died off, or just seemed to be taking traffic instead of trading.
Maybe a good idea for the new TGP owners would be to try trading traffic with each other. There are a lot of places that offer hookups for trades, but most of these guys are looking for HUGE amounts of traffic that a new site without many friends already running these things can not possibly deliver.
I am offering any new TGP owner the chance to trade traffic with my site, although it is a black site. I am also thinking about incorporating a TGP like gallery system on a couple of my blogs as well in the near future to add traffic to the blog and build trades. If you are interested in trading traffic now, you can signup
here.
This obviously won't grow your site to 100K overnite, but together sharing traffic with each other we should be able to grow to a size to start trading with some of the bigger sites, and step up incremently.