Google has an affiliate network, AdSense, which takes search listings and displays them on content sites. These sites range from high-end properties (e.g. www.NYTimes.com, see below) to low-end personal websites and blogs. Clicks from content ads can eat up a large portion of your budget and prevent you from being constantly listed under performing keywords in actual search listings. As a result, that can lower the overall performance of your campaign. So start your campaign without content targeting, then start adding performing terms to a separate campaign that has content targeting turned on. Then bid less for those terms in the content campaign. While the conversion rates of clicks from contextual listings can be far lower than clicks from search results, bidding less for them can make content targeting worthwhile if they still produce a viable cost per action.
