Here's an email I just got from Yahoo. Apparently the YPN is closing down for good after an extensive several year beta test.
Yahoo! continuously evaluates and prioritizes our products and services, in alignment with business goals and our continued commitment to deliver the best consumer and advertiser experiences. After conducting an extensive review of the Yahoo! Publisher Network beta program, we have decided to close the program effective April 30, 2010. We expect to deliver final publisher payments for the month ending April 30, 2010 to publishers no later than May 31, 2010. All publishers eligible for 1099s for the 2010 tax year will have those mailed by January 31, 2011.
Because our content will no longer be delivered to your ad unit spaces after April 30, 2010, we recommend removing all YPN ad code from your pages by that date.
For the opportunity to continue earning revenue, we suggest using Chitika, a leading advertising network that syndicates Yahoo! Content Match and Sponsored Search ads. Chitika has set up a special process for YPNO beta publishers to participate in its platform. Click here for more information.
We thank you for your participation in the Yahoo! Publisher Network beta. If you have any questions regarding this announcement, please contact our Support Team at (866) 785-2636, Monday through Friday from 7:00 a.m. to 5:00 p.m. PDT.
Your Partners at Yahoo!
Was anybody still using them anyway?