Violating the AdSenseTerms of Service (ToS) even by mistake can get your account banned or disabled. Once disabled, there's very little you can do to get your account reinstated. So how do you avoid getting in trouble?
Here are a few of the most common mistakes to watch out for.
A long-standing method of increasing CTR is to put AdSense ads near images. This is a bit of a grey area.
Yes, it's okay to put AdSense near your image ads and it will indeed increase CTR. However, it's important that they're far enough apart from each other that it doesn't imply a relationship.
For example, you can't put a picture of a bird cage up, then have an ad right underneath it that might display ads for bird cages.
Put ads near images, but make sure there's a line of text or enough spacing separating them that they appear to be unrelated items.
Disclosing CPM, CTR, Impressions, Clicks
This is data that Google considers competitive and doesn't want disclosed.
If you want to post earnings screenshots somewhere, just blank out those areas. You can still post screenshots of your URL channels along with their earnings, you just can't post any data that Google considers competitive.
Remember the Basics
Finally, always keep the basics in mind, no matter how long you've been doing AdSense:
Never edit the ad code. Never use any plug-ins that automatically generate code or edit the code for you.
Never place more than three ad units and one navigation bar on any page.
Never use any text other than "sponsored links" or "advertisements" above an ad box.
Never, ever click on your own links.
These are some of the most common mistakes that webmasters make which get their accounts disabled.