i want to make advert on yahoo?

[Cross]

i want to make advert through yahoo that will public my site to all countries most especially to all European sites

[Jake]

Microsoft owns Yahoo, you would buy ads covering Yahoo and Bing through the Microsoft ad center.

http://advertising.microsoft.com/

You can geographically target ads, so you can provide a different ad for different countries or regions.

Unless you have an optimized sales page that converts traffic to revenue, using a premium ad source like Yahoo probably will be unprofitable, creating quality content and using SEO techniques may bring you "free" traffic from search engines.