Search Engine Options
With AdWords, your PPC ads will show up on Google, AOL, Ask, and a few other small search engines, with Google far and away the largest. You can choose however, to show your ads on Google Search only if you choose. With adCenter, ads will show up on both Yahoo! and Bing, and you will not have control as to which search engine your ads appear.

Targeting Options
With AdWords, all targeting options are done at the campaign level. For example, enabling content, targeting time of day, changing bids by time of day or day or the week is all done at the campaign level. However, with adCenter you can choose these targeting options by ad groups.
And, with AdWords, you can only target geographical location, time of day and day of the week. But adCenter allows you to target all of those elements, as well as by gender and by age group.

Ad Types
AdWords allows for text, mobile, video, and image ads. With adCenter only text and mobile ads are available.

Ad Options
In AdWords, you can choose to rotate or optimize the ads within your campaign. adCenter will automatically optimize ads to show the ad with the highest CTR most frequently.

Dynamic Keyword Insertion
With AdWords you can use dynamic keyword insertion in the title of your ad. In adCenter, you can apply this to many more parts of the ads, including the title, the body of the ad and the destination URL based on search queries.

Dynamic Text
In adCenter, you have the ability to use placeholders to change many ads simultaneously. For example, many of your text ads for a hotel include rates that change frequently. Instead of changing each ad manually every time a new nightly special occurs, you can use a placeholder and update all ads at the same time. Click here for instructions on inserting dynamic text into your ads.

Copy Campaigns
You can automatically import your Google AdWords campaign into adCenter. Click here for step-by-step instructions.

adCenter Resources
Brand new information is available on the adCenter fall 2009 upgrade, including a tutorial and feature guide PDF for adCenter. Check out the Microsoft Advertising Community blog for all of this information.