Yes, I use it alot. It really helped me get rid of the RSS and blog ads on my blogs. Since, I start using it, my eCPM has doubled or more. Mind you, in that time, I've done a lot of things to make it double.
I have found it useful on some forums I have by targetting just the header and body of the posts. Also usually exclude headers and footers from consideration.
There two types of content on a page. There's filler (ads, headers, footers, sidebars). There's content. Put ignore directives around the all the filler. <!-- google_ad_section_start(weight=ignore) --> ... filler here ... <!-- google_ad_section_end --> You can then break the content into titles and other content. Put emphasize directives around the titles. <!-- google_ad_section_start --> ... title here ... <!-- google_ad_section_end --> I've experimented with different variations of what I include in the emphasize directive. For instance, some content has a title, a description and other. And I've emphasized the title and description. In another case, the content had tags and I emphasized the tags, not the title and not the description. Titles seems to work best.
thats great information randymorin, thanks for helping so far. 1 question though.. if i would like to ignore the footer for a specific page range (using a specific ad-channel) how should this information get added to targetted adsense ? Thanks again.