Yahoo Publisher Network has been around since 2002. It is currently in beta. What that means is you have to be accepted into the program and create and maintain a quality site.

Yahoo publisher Network is similiar to Google Adsense. It’s got many similiar ad block sizes. It is contextual, meaning the ads are targeted automatically for the content on your page. One feature they have that Google adsense does not is that you can specificy for certain pages a ad category. In other words if you don’t want it to target something related to the content on your page, you can choose an ad category to target to them instead.

Yahoo Publisher Network based on my personal experience pays similiar rates per click to Google adsense. However, their contextual targeting isn’t always very effective, maybe because of the size of the advertiser pool. As a result, overall total earnings often are lower compared to Google Adsense.
On some sites though, Yahoo publisher network does just as good as Google adsense. It depends on the niche and how many relevant ads Yahoo can bring up for your topic.

Yahoo Publisher Network maintains high quality sites. It is only open to U.S residents and the traffic you must receive should be very high, like in the 90%+ range. Until YPN comes out of Beta, I recommend to save it as a reserve, just in case you get banned from Google adsense and can’t get back in after trying to appeal your case.

Which is better Yahoo Publisher Network or Google Adsense?

1) Google Adsense has more ad unit choices. Adsense also has a search button that YPN doesn’t.

2) If you get banned by YPN you can come back once it is out of beta, unlike Google where bans are for life.

3) Yahoo you need high quality U.S traffic and be a U.S resident, Google Adsense has no such requirements.

4) Not every website is accepted into Yahoo, Although Adsense has strict requirements too, they are not as rigid as YPN.

5) Google Adsense has better ad targeting (and thus click through rate). As a result, GA usually pays better overall.