Making money online through Adsense and other ad networks

Some of my friends are running a couple of forums with adsense on it and i asked them the performance.    According to them, it is fine to use Adsense Ads on a forum however expect a very low CTR.   The usual place for ads in the forums is the top most area using 728x90 banner.

Most forums are characterized by frequent repeat visitors and these people are most likely disregarding your Adsense advertising because of banner blindness.  The highest clickers are those that are new to the board or are first time browsers.

To have better results,  you need to tweak your forum software to have ads shown in between forum posts just like what http://forums.digitalpoint.com did.   They also made the banner ads stand out by using contrasting colors to prevent banner blindness.