Especially around the last minute holiday crunch, advertisers are often looking to maximize their ads' exposure to targeted audiences. To that end, they often contact our friends over in AdWords support to ask how their ads can appear on other Google properties, like Froogle and Groups.
Well, it's simple: the Google search network not only includes partner sites, but many of Google's own properties as well. And as long as your campaigns' distribution preferences includes our search network, they're eligible to appear for searches on Froogle, Local, Book Search, and Groups.
In addition to these Google sites showing keyword-targeted search ads, your ads can also appear alongside the content of books on Google Book Search and related to discussions in Groups and Gmail as long as your campaigns are opted into appearing on the content network. These contextually targeted ads work the same way as ads on content pages across the web -- the keywords you provide in your campaigns are automatically matched with the content of books, postings, or emails on Google's pages, and the ads which most closely match the subject at hand are eligible to show.
As always, the goal is to provide users with useful, relevant ads, whether they're browsing books, looking for the local dry cleaners, shopping for holiday gifts, or checking their email with Google.