“Google AdSense is for someone who wants a complete solution. It might not fill all of your ad inventory (well, maybe, now that you can have up to 3 units served on a page), but it will do good with what it does fill. It’s simple, easy, and all encompassing. With fluxuating EVERYTHING, it’s difficult to produce a larger yield then well targeted Sale/Lead affiliate programs. That being said, it’s an excellent program for webmasters who rather focus on content. It’s potential revenue power is, however, extraordinary.”
Read more at Google AdSense Review – Go4-Webmaster.com
I’ve been using Adsense for close to a year now and find that it is very useful on some blogs but next to useless on others. I’ve got friends who run niche blogs on highly targeted subjects (sometimes quite localized on particular countries) and they have struggled to have any ads served to their blog. As with any contextual advertising it largely depends on your content as to whether it will work or not.
Get some good Adsense tips in our Adsense for Bloggers tutorials.