Some ways to remove PSA, written by quickonlinetips.com:
- Develop sufficient good content with keywords on your webpage related to the topic of interest
- Ensure that META tags like ‘title’ & ‘description’ and the headings tags like h1, h2 etc. have content which matches the rest of your site
- Add specific keywords in your text which will help the google bot to determine and understand the content of your website
- Try to keep the entire website focussed on a particular theme, so that even if the content on a particular page is lesser, the ads wil show
- Do not place multiple ad units if there are not suffcient ads to display on all of them
- Use section targeting - you can target an ad unit to a specific section of your blog, as well as block out irrelevant sections like navigational links
The complete article is here, along with the reason why we must remove the PSA ads.