Google is widely used as compared to microsoft and yahoo. Hence, google has a wider reach and thats why google is global. You see why many people optimize a website for google? You can check your site links on all the engines google, bing and yahoo by site:yourdomain.com and you will find google displaying more links than yahoo. Bing will show the least. So go for google, dump yahoo and bing, i feel they are useless. Anyways, ask yourself if you have ever used bing or yahoo for searching? Everyone here would agree that they use google more for searching online. The funny thing is even on digital point the more people are viewing Google forum than Yahoo and Microsoft combined. I think that is why YPN and Adcenter are not global... And yahoo and microsoft knows why, or else they would have certainly made it global to compete adsense.
thanks for the info...any news when the microsoft publisher ads for bing might become available for european publishers?