Yahoo! Search Marketing
There are two network options for Yahoo! Search Marketing:
All Yahoo! campaigns must include the Sponsored Search network, which will display ads on search results pages on Yahoo.com.
If you activate Yahoo!'s Content Match feature, your ads will appear on websites, newsletters, emails and other related content throughout the Yahoo! content network. Your ads will not be triggered by keyword searches, but by a similarity between the content of your ads and the content of the affiliate material.
As with Google AdWords, you can also activate "Content Bids" (described above) along with the Yahoo! Content Match network.