Yahoo sends to your web browser most of the advertisements you see when you use the Yahoo network of web sites. However, we also allow other companies, called third-party ad servers or ad networks, to serve advertisements within our web pages.
Because your web browser must request these advertising banners from the ad network web site, these companies can send their own cookies to your cookie file, just as if you had requested a web page from the site.
Please note that if an advertiser asks Yahoo to show an advertisement to a certain audience (for example, men ages 18-34) and you respond to that ad, the advertiser or ad-server may conclude that you fit the description of the audience they are trying to reach.Opting Out of Third-Party Ad Servers
If you want to prevent a third-party ad server from sending and reading cookies on your computer, currently you must visit each ad network's web site individually and opt out (if they offer this capability).
Currently, Yahoo Canada has relationships with the following third-party ad networks: