Just got this in the mail, and set up a test campaign. Sounds very exciting!

Dear AdWords Advertiser,

You have been selected to test Site Targeting — a new AdWords feature that will allow you to easily target your ads to specific content sites across the Google Network, giving you a new way to reach people who will find your ads relevant and useful.

The Site Targeting feature consists of the following components:

Site Targeting

You can select specific content sites across the Google Network where you would like your ads shown. This lets you connect with people who are likely to be interested in your product or service.

Impression-Based Bidding
With site targeting, you set a maximum CPM — that is, the maximum price you are willing to pay for every thousand impressions your ad receives on a particular site. Your ads compete for placement on a site with other CPM and CPC ads in Google's auction. Google's approach is different from other CPM models, where advertisers must pay a fixed CPM. On AdWords, you pay no more than the minimum price needed to run an ad on a site.

New Ad Formats
In addition to text-based ads and static image ads, you can run animated image ads within your site-targeted campaigns. This is an enhancement to the image ads option we introduced last year. Image ads are carefully evaluated before they are allowed to run on content sites in the Google Network.

Getting Started
Site Targeting is not yet available to all advertisers — but you can get started today by following the instructions below. If you are not an AdWords advertiser, please sign up for AdWords or learn more.
Log in to your AdWords account.
Click 'User Preferences' under the 'My Account' tab.
Click 'Edit Campaign Type' above the AdWords Terms and Conditions.
In Section 5, 'Where to show my ads,' locate the checkboxes below 'Show ads on Google and...'
Click the checkbox next to 'Enable site-targeted campaigns' and 'Save Changes.'
This will change the 'Campaign Types' setting.

All new campaigns that are created will now give you the option of selecting whether you would like to create either a keyword-targeted or a site-targeted campaign.

More information on Site Targeting can be found at http://www.google.com/adwords/sitetargeting. Contact your AdWords representative or AdWords support if you have further questions.


Thank you,
The Google AdWords Team

Now these campaigns are called placement targeted campaigns.
But be careful as this kind of campaigns are CPM campaigns by default.
But you can switch from CPM to CPC if you want.

You can?? I was under the impression that placement targeted campaigns are always CPM based.

Hi!

Yeah you can indeed. For your info here is the link to the help centre section about this:

CPC Pricing for Placement Targeting

all this is related to a publisher eCPM ("effective cost per thousand impressions.")
eCPM explanation for AdSense publishers

That first one isn't in English.