Biggest AdSense Mistakes
No matter how many alternatives for Adsense that you can find nowadays, this ad network by Google is by far still the best contextual ad network for bloggers and the highest paying one. 
However, Adsense is very strict when it comes to its policies, when you do something that’s considered as a violation to the Adsense TOS, your account could be suspendedimmediately. Getting your Adsense account suspended is pretty much like a nightmare especially if you have a huge balance because you will not be able to get the money. Plus, there is a very small chance that your account can be re-activated.
on how to get your banned account back online - and how you can easily and safely open new YouTube/AdSense account. So it would be wise for you to avoid making mistakes that could get your Adsense account suspended. Here are some of the most common mistakes that you should avoid if you still want to keep your Adsense account active:
Adding too many AdSense Ads on your website
Adsense has a rule about the maximum number of ad unit that can be displayed on a single page. The rule is actually quite simple to understand, Adsense categorizes its ads in Adsense content unit, Adsense link unit and Adsense for search. Each of these categories has a maximum limit of ads to display. However, having ads more than the maximum limit is usually a mistake from the system, and ideally if you see something like this you should report it just to show a good gesture.
Encouraging to click within the text of the website
There are a lot of things people do to encourage Adsense click, they could put it within the text, or putting Adsense in pop up messages and visitors must click them to find the content, or using the ‘click here’ trick. These are all strategies that Google is already familiar with and they will get your account suspended.
Having copyright infringing content or not unique articles on the website
Google is very strict about websites that are hosting and distributing copyright infringing content, also those having duplicate content. Such websites are even banned from Google’s search results, so obviously they will never put their ad content on these websites.
Buying fake clicks (also clicking on your own ads)
This is one dirty trick that has been a problem probably since the first time Adsense was introduced. People are asking their friends to click on their ads or they click their own ads using different IPs or even buying fake clicks. Even though sometimes it may take time for Google to catches you, they will eventually does, they always does. Google is very serious about preventing such practice because it’s very bad for the advertisers.
Using multiple Adsense accounts
Google only allows one Adsense account per entity or person, the rule is very clear and straightforward. They don’t even allow 2 persons with the same address for having two separate accounts. Having multiple accounts or trying to get multiple accounts will get ALL of your accounts suspended. If probably you make a mistake and accidentally applied more than once for an Adsense account, then it would be best if you message them and let them know what happened.
Resources:
http://www.theregister.co.uk/2015/09/29/adsense_fraud_still_too_easy_says_spanish_boffin/
http://marketingland.com/yet-another-publisher-sues-google-withholding-adsense-earnings-113994
