Yahoo! Sponsored Search is a form of search engine marketing that lets you create ads that appear in search results on the Web’s most popular destination and other sites in the Yahoo! distribution network. So you can attract people who are already searching for what you sell.
AdWords is Google’s flagship advertising product and main source of revenue. AdWords offers pay-per-click (PPC) advertising, and site-targeted advertising for both text and banner ads. The AdWords program includes local, national, and international distribution. Google’s text advertisements are short, consisting of one title line and two content text lines. Image ads can be one of several different Interactive Advertising Bureau (IAB) standard sizes