adsense has the option of putting an alternate ads via the "alternate url" when there is no ads/public ads svc.... I have a blog on health, basically google only allow 3 ads units per-page, hence i use the alternate url function in order for the 4th/subsequent ads units to display other ads rather than a blank space there. However, it doesn't show other ads that i have created from which i had loaded to my server, indeed the 4th ads unit show nothing and a big blank space there...... my site url: www.healthcare-article.com or do i get the concept wrong, meaning whenever the are not ads from google even the first ads unit, only then my alternate ads will show up...... pls advise.....