Microsoft AdCenter is launching ContentAds (a contextual / AdSense competitor ) later this month.
As I warned a while back, AdCenter's default is to automatically add content ads distribution to your AdCenter campaigns.
You can avoid this potentially costly situation by opting out.
We're excited to announce the release of the Microsoft Content Ads Beta to all U.S. adCenter advertisers on August 29! With this release, you can extend your advertising reach beyond search, and choose how your accounts are upgraded.
Choose how you want to upgrade
On August 29, you don't have to make any changes and your ad groups will automatically expand to hybrid distribution, meaning they will distribute to search and content pages.
You have to fill out a form so that your account can be "upgraded" without content ads enabled by default. Here's the message you get:
Thank you for completing the Content Ads: Upgrade to Content with only Search Distribution Active form.
Your adCenter ad groups will be upgraded to Content Ads, but Content distribution will be turned off at the time of the upgrade. If you wish to turn on Content Ads at a later time, you are welcome to do so. Remember that all new ad groups created after the upgrade will be set to hybrid (expanded to both our search and content network).
They certainly are going out of their way to make it hard to not be automatically in ContentAds...