There is another common mistake I would like to add to my previous entries – 18 Common Mistakes that violate Google Adsense Terms. It is regarding “Google Brand Features” issue.
I applied for an Adsense account for this blog and was surprised that they rejected my application with the following reason:-

Google Brand Features: We’ve found that [...]

I will leave this to Mr. WikiPedia:
AdSense is an ad serving program run by Google. Website owners can enroll in this program to enable text, image and, more recently, video advertisements on their sites. These ads are administered by Google and generate revenue on either a per-click or per-thousand-impressions basis.
If you notice, which I am [...]