I expected the Bing/Yahoo! search alliance to begin early Q1 of 2011. Apparently things are ahead of schedule as I just received this notice for Microsoft AdCenter.
This is an exciting week for Bing as we reach another major milestone in the Yahoo! and Microsoft Search Alliance. This week, Bing will begin powering organic search results on Yahoo! Search for the English language in the United States and Canada.
After this organic transition is complete, Bing will power 5.2 billion monthly searches, which is 31.6 percent of the search market share in the United States and 8.6 percent share in Canada.1 You can take advantage of this traffic by using search engine optimization (SEO) to complement your search campaigns and boost the visibility of your business. Bing webmaster tools can help you troubleshoot the crawling and indexing of your site, submit sitemaps, and view statistics about your sites—all to improve your visibility on Bing. Get started by visiting the Bing Toolbox or watching our video.
Advertise on Yahoo! Search and Bing through adCenter
If you currently advertise on Yahoo! Search, you will soon have the option to use a transition tool in Yahoo! Search Marketing that will walk you through the steps to transition your Yahoo! Search campaigns into Microsoft Advertising adCenter. This transition tool is currently in testing with a select group of advertisers. We plan to make it available to all Yahoo! Search Marketing advertisers in the coming weeks, giving you the ability to advertise on Yahoo! Search and Bing with one adCenter ad buy.To help you prepare for a successful transition, please continue to work with your existing support contacts and visit the Microsoft Transition Center for the latest information about the new marketplace. Remember, our primary goal is to provide you with a quality transition experience in 2010, while protecting the holiday season. However, if we conclude that it would improve the overall experience, we may choose to defer the transition to 2011.
We appreciate your business and look forward to bringing you the benefits of the Yahoo! and Microsoft Search Alliance.
Sincerely,
Your partners in the search alliance, Yahoo! and Microsoft

