There are a lot of gaming websites popping up online as time goes on, and a lot of these sites are struggling for traffic. If your a cheap person and only want to use free resources, there are plenty abound.
Youtube and Google Video can generate you a lot of hits if you have video that is worth seeing, such as convention showings, game reviews, and so forth. Something that draws the people to your site to find that extra tidbit of information. Another is going to various other gaming sites across the net and toss a short summary about the article and a link back to your site. Be sure to don't advertise this too greatly on your competitions site, I'm sure you wouldn't want the same done to you either.
There is yet another method of getting a LOT of free traffic, using sites like www.fohguild.org and www.legionofsteel.org which have a substantial userbase and can net you a large amount of traffic. This is usually an untapped resource that isn't usually used by most marketers, since people usually think that guilds are small in nature, which can be true for the most part, except for those rare mega-guilds that have several hundred members, tens of thousands of hits per day, all by themselves.
The best type of marketing is viral marketing, gaming in general is usually like that. Someone see's something interesting on your site, they link it in some random forum, more people see it on their forum, and they link it onward. You just need to be able to plant the seeds in some nice fertile soil, such as other popular high traffic sites (fansites, mega-guilds, etc).