The key to success with Adsense is the placing of ads on pages that are receiving high traffic for high demand keywords. The higher the cost-per-click to the advertiser, the more you will receive per click from your site. Obviously, it does not pay to target low cost-per-click keywords and place them on pages that do not receive hits.
Kevin's Papers
Technical Papers by Kevin Morrison
Considering the money to be made with Adsense, it is no wonder that they would want to get back into it. It is that same consideration why the Google Adsense click fraud is thought of and why many people are getting into it.
For this same reason, doing the wrong things in the Adsense and other forms of advertisements, whether intentionally or unintentionally, will result in a severe penalty, may get you banned and even have your account terminated. Nothing like a good action taken to keep wrongdoers from doing the same things over again.
The ones who have been there and done it have quite some useful tips to help those who would want to venture into this field. Some of these tips have boosted quite a lot of earnings in the past and is continuously doing so.
To know why Adsense is essential for your content sites is to know first how this works.
The concept is really simple, if you think about it. The publisher or the webmaster inserts a java script into a certain website. Each time the page is accessed, the java script will pull advertisements from the Adsense program. The ads that are targeted should therefore be related to the content that is contained on the web page serving the ad. If a visitor clicks on an advertisement, the webmaster serving the ad earns a portion of the money that the advertiser is paying the search engine for the click.