To compete with Google, Yahoo has also introduced the Adsense named Yahoo! Publisher Network(YPN). Although, it is in beta mode.

One of the products in Yahoo's beta is Content Match, which allows publishers to place contextually relevant listings on their sites and receive a part of the revenue generated by them. Another feature, "Add to My Yahoo," is designed to let them promote and distribute their content on Yahoo via RSS (Really Simple Syndication) to drive traffic to their sites.

But if you wish to join the YPN then you must be a resident of the U.S., with valid U.S. Social Security or Tax ID number.

So, what next? Google Messenger or Yahoo Earth ;)