A simple tip from me. Register and post on games forums and link your sites in your signature. Signature advertising is especially good for getting traffic, in my opinion. Also, you may hire our some posters that will post on various sites and include a link to your site in their signature. Maybe a banner exchange, of course many people say this isn't worth a darn, but, personally, I STILL click on banners! These are free methods mostly. How is your content on your site? Have you thought about ezine articles?