Like most income streams though, there are always people out there who do their best to take advantage of the system in any way they can to maximize their earnings. Exploiting systems by taking advantage of the shortcomings or bugs in the system is generally a short term deal. As soon as the supplier finds out that they are either not getting or not providing value for their service, they will very quickly close any 'holes' and fix the bugs. When you take into account the millions of dollars that are generated from Adsense ads each month, it goes without saying that Google will go to great lengths to ensure that their advertisers are getting good value for their advertising dollar.

With this in mind, if you intend to monetize your site with Adsense and want this to be a long term income strategy you need to be familiar with the terms and conditions. Lets strip away some of the 'legalese' and take a look at some of the policies, requirements and also the type of activity that may cause your account to be terminated.

* Up to three ad units may be displayed on each Web site page - that's pretty clear. You can have up to 3 ad units, regardless of size or placement, on each of your web pages.

* A maximum of two Google AdSense for search boxes may be placed on a page - again, that's easy enough to understand. The search boxes are the ones that allow you or your visitors to search the Internet or your web site using a Google Search box on your web page.

* A single link unit may be placed on each Web site page, in addition to the ad units and search boxes - the link units are a different format to standard adsense units. They provide just the link with no URL or additional text. You can have one of these in addition to your adsense ads and search boxes.

* A single referral button per product may be placed on a page - Google will pay you for referrals, but you are allowed only one referral link on each web page.

Those policies spell out what you are allowed to do. Now let's look at things you aren't allowed to do. From an advertiser's point of view, the quality of the page their advertisement is displayed on will bear a relation to the quality of the visitors who actually click on this page. This is one of the reasons you are not permitted to place ad units on pages that have no other content. The rule of thumb is that you should only be placing ad units on pages that contain some sort of valuable or useful content.

The reality is that it is in your interest to provide useful content. The better your content is, the more likely it is that it will appear higher in the search engines. This in turn brings you more traffic and the traffic you get is mostly people who are interested in the subject matter of your site. These also happen to be the people who are most likely to click on your ads simply because they have come to your web site looking for information and/or products.

Other things that you need to avoid in order to protect your account include:

* Never place ad units on pornographic, racist or hate related sites.

* Never place ad units on error, registration or 'thank you' pages. Remember, the advertisers want their ads on useful, relevant pages. Common sense should tell you that these pages are neither relevant or useful for advertising. It's a bit like placing an ad inside a cabinet. Nobody goes there looking for information or products!

* Never click on any of the ads on your website. This is considered fraud (for obvious reasons). If you do accidentally click on an ad, make sure you contact Google support immediately and let them know which page and the date and approximate time.

* Never place ads on pages that you display in Traffic or surfing/hit exchanges. This is mentioned in the policies and is not permitted.

I hope this information has been useful. Adsense is a great way to earn some extra income, but you need to make the effort to ensure you are within the terms and conditions. At the end of the day, common sense should give you a good indication whether you are doing the right thing with Adsense ads