My main traffic source is the Minecraft forums. You just need to find the right site to post a few comments in threads that targets your audience. We posted a few threads, and everyone else did the work for us. Alas, the 80$ bandwidth bill hasn't been paid for by the site, so that is why we are looking for advertisers. We get a good amount of click throughs, about 5-10 daily.
Yeah, I get a lot of traffic from strategic postings in the minecraft forums for my own minecraft website as well. Getting around 2000 pageviews/day now, so hopefully someone will be interested in advertising on it once the advertisement slot is approved.