I have an insanely large ammount of bookmarkers and my site is thumb preview TGP that skims 50% to trades.
5k per day total and 1k of that is bookmarkers. I don't know why.. but that's 1k with no referer and no trade cookie.
http://www.coedcherry.com
So I disagree about trade skimming pissing off surfers. In fact most of my friends don't mind trade skimming at all.. they just look at it as more free porn when they end up at another TGP. And if they like your design and the galleries you list there's no reason they won't bookmark you.