I've created a new marketing service specifically for game developers. Follow the link to read the explanation of services. http://www.nominalgames.com/ad_promo.html
To summarize, I basically run an ad campaign for 6 game developers at a time. Each developer contributes $50. I put together a campaign using buysellads.com and $300.90 will get about 1.25 million impressions on 8 different game sites. Even with only a 1% click-through rate, that's about 12,500 visitors.
The ad will take visitors to a landing page on my website that has a Youtube video composed of 6, 10 second clips, one for each game. Below that is a description and link to each website along with a twitter feed that displays tweets from each developer. Go here to see an example of the landing page http://www.nominalgames.com/indiepig.html
I do not charge any fees for my services. The $50 goes directly to buying ad space.
If you have any questions, feel free to drop me a line: