The Yahoo! ad serving transition to Microsoft Advertising adCenter is now complete. You must now use adCenter to manage your campaigns so that with just one buy, your search and content ads will reach users on Yahoo! Search, Bing, and other premium partner sites and networks. Your Yahoo! Search Marketing account is now in a read-only state which means your adCenter account is the only one you need to manage in order to advertise on Yahoo! Search and Bing. If you have not completed your account transition to adCenter, you must log in to your Yahoo! Search Marketing account and transition now to continue to advertise.
We've created a detailed Transition Checklist you should review, to help ensure that you're prepared to make a smooth transition to Microsoft adCenter, as well as a Feature Comparison Guide, to help you get familiar with Microsoft adCenter's features and capabilities. You will also need to download Microsoft Silverlight, the tool will allow you to see and address key differences between your Yahoo! Search Marketing and Microsoft adCenter campaign setups. Install Silverlight today, it is easy to do and at no cost to you.
- Prepare your account for transition to Microsoft adCenter
When you log into your Yahoo! Search Marketing account, you'll automatically be taken to a new tab labeled "adCenter." You can review the Compatibility Report and fix incompatibilities between your current Yahoo! campaigns and the Microsoft adCenter platform before transitioning to Microsoft adCenter.
- Transition your account to adCenter
You can create a new Microsoft adCenter account, or indicate that you have an existing Microsoft adCenter account that you'll continue to use. You can use the transition tool to copy your Yahoo! Search Marketing campaigns over to Microsoft adCenter. Please note that once you do so, your new Microsoft adCenter account will be active and your campaigns will retain the same status (active or paused) as they have within your Yahoo! account, so you may need to un pause them to begin advertising on Yahoo! Search, Bing, and premium partner sites.
We appreciate your business, and hope you enjoy the benefits of the Yahoo! and Microsoft Search Alliance. | 
