Yahoo! sent out an email this morning informing me that their Yahoo! Publisher Network (YPN) Beta program will be closing down at the end of April. Yahoo! is also referring all of their current publishers over to Chitika, who they’ve named as the leading network which syndicates the Yahoo! content match and sponsored search ads.

I’ve been part of the YPN Beta since it’s launch in 2005, and while I’ve found that for me it hasn’t been as big of an earner as AdSense I do know a handful of people who have been using YPN exclusively on their websites since the program’s launch. I’m wondering how these publishers are going to react to this news. Will we be seeing a lot of these publishers go back to AdSense, or will they join Chitika? I guess the better question is why did Yahoo! refer their publishers to Chitika when they have a partnership with Microsoft and could just as easily refer them to Microsoft’s pubCenter Beta instead?