Google's AdSense is perhaps the fastest and easiest way to generate revenue from a website that contains great content.

If you'd like to see an example of Google AdSense in action, visit this page about what is the best day to purchase a cars. On the left side of the page, you'll see "Ads by Google" followed by one to five text-based ads. The ads themselves are called "Google AdWords," and the program that lets publishers display them on their site is called "Google AdSense."

Here is how Google answers the question -- what is AdSense -- in its FAQ (frequently asked questions):

" Google AdSense is a fast and easy way for website publishers of all sizes to display relevant, un-obtrusive Google ads on their website's content pages and earn money. Because the ads are related to what your users are looking for on your site, you'll finally have a way to both monetize and enhance your content pages.

"The program is free, and combines pay-per-click and pay-per-impression advertising - meaning you get paid for valid clicks on the ads on your site or search results pages as well as impressions on your content pages. So go ahead and try this program."