Very similar to Adsense. Main difference - there are some geographical restrictions who can be accepted to YPN.

Produce additional income by displaying ads associated to the content on your web site.

Benefits

• Raise your profits by monetizing the content of your web site.
• Satisfy your users by offering them ad content related to their interests.
• Leverage our knowledge of how best to optimize your contextual advertising.
• Get paid quickly via a convenient PayPal payment option and earn a return on the money in your PayPal account by depositing your funds in PayPal's Money Market Reserve Fund.

Features

• Advanced ad targeting and display capabilities can improve the relevance of your results.
• Ability to filter competitive listings from appearing on your site—to protect your business.
• Access to a wide range of tools, services and programs that enable you—and your users—to get the most value from your site.
• Four ways to collect your revenue, including a PayPal option that lets you get paid more quickly.