What you pay for each AdWords Cost Per Click (CPC) is determined by you! How frequently your ad is served is determined by the maximum CPC and your ad’s daily budget. You can select to show your ads globally, nationally, regionally, or even in a targeted area determined by your address or by latitude and longitude.
Not only does Google show your targeted keyword ads in its huge search network consisting of additional partners like AOL, The New York Times, and Amazon.com, but your ad (after about 2 days) could be shown in Google’s Display network and on websites showing Google AdSense ads. Your ad will appear on sites like The Washington Post, Forbes.com, CNet, private websites, shopping comparison networks, and even in e-newsletters.
Your CPC is less when your click comes from the display network and is even based on which site delivers the highest documented click through rate.