You must mean the Yahoo! Publishers Network. Good question and I am certain that you will get a lot of different answers. YPN has worked well for me on some sites, but not for others. Just yesterday I replaced the theme on my automotive blog and increased by display of YPN ads. Immediately, I noticed an improvement in clicks and had my best day in more than a week's time. Yes, too early to tell but I also added fresh placements along the sidebar and in each post. I believe YPN can be a decent alternative to AdSense, one that I plan on expanding to other sites I manage in the near future. I hope this information helps you. Feel free to visit the blog to see what I mean.
No, he is asking for overture keyword tool, as I have understand. You can use it for some general investing, but its not completelly accurate