The Yahoo Publisher Network (YPN) notified its publishers that the program will cease to operate starting April 30, 2010. The program seemed to be in full swing back in 2007 but has since fallen out of sight - perhaps thanks to the introduction of the APT platform.
In the email notification to publishers, Yahoo! suggested using advertising network Chitika, a well respected contextual network which happens to syndicates Yahoo! Content Match and Sponsored Search ads. Chitika has set up a special process for YPNO beta publishers to participate in its platform.
Should you still be using YPN, expect the final 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.