As of May 27, 2006:
According to Google:
Your ads may appear alongside or above search results, as part of a results page as a user navigates through a site’s directory, or on other relevant search pages. Our global search network includes Google Product Search and Google Groups and the following entities:
America Online (AOL)
AT& T Worldnet
Google Adwords allows advertisers to target Google searches, their search network partners and their content network at the campaign level under the “Edit Campaign Settings” tab.
Every campaign and keyword performs differently.
I have found measuring the performance of each is necessary to successfully managing keywords let alone campaigns.
Tags: Search Marketing