You can choose to show your ads to the entire world or limit their exposure by country, region, state, and even city. You can (for example) let them run 24/7 or turn them off nights and weekends. You also get to choose from AdWords' three tiers of exposure, described in the following sections.
When someone searches for a particular keyword, your ad displays on the Google results page if you've selected that keyword (or a close variation) as a trigger for your ad. For the ad shown in Figure 1-1, if someone enters barefoot running in Google, he can view the ad somewhere on the top or right of the results page (see Figure 1-2).
Your ads can also appear on Google's search partners' network. Companies such as AOL and EarthLink incorporate Google's results into their search pages, as in Figure 1-3.
A partial list of Google search partners includes
Additionally, hundreds of thousands of websites show AdWords ads on their pages as ...