Promoting apps

I am sure there are plenty of ways to get your application promoted on a website for a certain amount of money. But, considering, I am releasing free applications that are mostly ad supported, I started to wonder if there are any viable free ways to promote apps.

So far I am looking at 2 main places:

• Forums, such as Android Community, Anddev.org and others
• In-house advertising

First option does not really bring the volume of people that is needed considering the ad supported nature of my applications, while in-house advertising is proving somewhat ineffective. It's causing revenues to drop significantly and isn't providing too many additional installs. 

Still I will be running in-house ads for the duration of this week and will post results here.