PSA stands for Public Service Ads which mean you will get nothing if peoples click on those ads. These ads will appear on your site if there is not enough contents or adsense crawler has not yet crawled to your website pages.
Beside you can fill the ads with solid color, you can remove the PSAs with this following code:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd ">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
<body style="background-color: transparent;">
Copy the code above and save it as a html file. Eg: adsense_script.html.
Upload it to your website (usually in root, eg: www.website.com/adsense_script.html)
Setup your Adsense ads as usual.
In the “Show non-Google ads from another URL”box, type in the html file url.
With this, the PSAs will not show up because they have been replaced with the script above. 🙂
[via Malaysia Bloggers][tags]adsense, public service ads, tips, how-to[/tags]