Google AdSense - review 

Google AdSense is a program for web publishers, or indeed anyone who owns a webpage, to earn an income from the traffic you have on their site.

About AdSense:
AdSense is a pay-per-click network, meaning publishers earn only when the contextual advertisements on their pages are clicked by visitors to the site.
Each time a click is made on an advert a small cash amount is added to the publishers account.
AdSense advertisements are shown on lots of sites around the net, including on the websites of many big-name multinationals.
These ads are distinguishable by the text 'Ads by Goooooogle' (yes 6 "o"'s appearing next to the text advertisements.

Adsense formats:
There are several different ad formats or layouts, enabling publishers to fit the ads around their existing comment.
The 'theme' or colour scheme for the ad units is also customisable to ensure the ads fit in alongside the existing page design.
Possible formats: Standard 468x60 banners (upto 2 ads)
Leaderboard 728x90 banners (upto 4 ads)
Skyscraper 120x600 (upto 4 ads)
Inline Rectangle 300x250 (upto 4 ads)

Adsense ads: text ads, banner ads, link ads, video ads - new

Possible income: AdSense rates and payments are not disclosed by any publisher. You can generate from 0 - 1000s of USD per month.
Income depends on traffic volume, website and content quality, CTR and keywords. Possible click reward: USD0,05 - USD15.

Highly paid sites:
- Automotive
- Insurance
- Investing
- Currency market
- Lawyers related websites

Overal rating: 4/5 - honest opportunity with long history. Recommended for often visited websites. The great disadvantace can be some publishers are banned without real reason.