Google requested advertisers fill out a form if they would like to test the new site targeting model. Currently, the default model for site targeted campaigns are CPM (impression based). But they wanted to expand that to a CPC (click based) model.
What is site targeting? As explained, it "lets AdWords advertisers choose individual sites in the Google content network where they'd like their ads to appear. If you want to place your ad on a single international website, you can. If you want to select dozens of sites about basketball or orchids, you can do that, too. Site targeting lets you handpick your audience, big or small."
How do you set it up? As explained;
(1) Sign in to your AdWords account. (2) On the Campaign Summary page, click site-targeted in the 'Create a new campaign' section near the top of the page. (3) Follow the sign-up wizard instructions to target users, write your ad, and select sites for the campaign. (4) On the page titled 'Choose a Pricing Method,' select CPC and click Continue. (5) On the following page, enter your preferred amounts for your daily budget and maximum cost-per-click. Click Continue. (6) Review your selections and complete the campaign creation process.