Microsoft announced the UK, France and Ireland search ad transition from Yahoo Search Ads to Microsoft adCenter ads will begin this Wednesday and should be 100% completed by the end of this month.
Microsoft explained:
Next week, we begin to shift ad serving for Yahoo! Search over to Microsoft Advertising adCenter. This means that adCenter ads will gradually be displayed on Yahoo! Search result pages in the UK, France and Ireland. This process will begin as early as the 18th of April and is expected to conclude during the last week of the month when 100% of the Yahoo! traffic will be made available in adCenter and Yahoo! Search Marketing accounts will go in read-only mode.As Yahoo! ad serving moves to adCenter, and your clicks and impressions in that account begin to increase, you’ll see a corresponding decrease in clicks and impressions in your Yahoo! Search Marketing account. It is thus important to continue managing your campaigns across both platforms throughout this transition phase, in order to avoid missing out on any potential clicks. To help you prepare, I wanted to share the following guidance to assist you through this transition.
This transition has been happening throughout the various regions, first with the US in October 2010 and is still lingering on and on.
Forum discussion at WebmasterWorld.