kodaks - 10:19 pm on Apr 22, 2005 (gmt 0)
In my limited testing of YPN (Yahoo Publisher Network) I have noticed that the ads default to commercial ads of very generic variety (i.e. ISP offers, loans, online degrees) when the page has not yet been spidered.
Thats not very surprising as they are a very new service being developed. They probably have not built up a large database of potential advertisers as of yet.