In a surprise move, Bing has become the default search engine for AOL and its “portfolio of sites” for ten years, according to a blog post by Microsoft.

Bing will now power search and search advertising across the AOL portfolio of sites.  This 10-year agreement will enable AOL users to have access to world-class search powered by Bing across the company’s global portfolio of sites. Now with 20% organic market share in the U.S., Bing continues to grow organically as well as through key partnerships like the one with AOL. This deal with AOL is the latest to validate the quality of Bing results and the performance of the Bing Ads marketplace. Bing is also an integral part of popular first and third party devices and services.

This change includes not just the AOL proper site, but Microsoft’s announcement specifically includes Huffington Post, Engadget, Adap.tv and TechCrunch for websites using Bing as default search and Microsoft’s “much-loved consumer services” MSN, Xbox, Outlook.com and Skype.

But the most interesting part of the deal is that AOL will take the display business from Microsoft and will sell display, mobile and video ads for Microsoft’s properties in the US, Brazil, Canada, France, Germany, Italy, Japan, Spain and United Kingdom.

This also means that current Microsoft employees working in display will receive AOL job offers to join the newly created AOL display ads team.  “All of Microsoft’s roughly 1,200 advertising employees — from engineering to sales — will be getting offer letters to join AOL, according to a person familiar with the matter.”

AppNexus is also part of this deal.

With our expanded AppNexus partnership, they will become our exclusive programmatic technology and sales partner in 10 markets (Austria, Belgium, Denmark, Finland, Ireland, the Netherlands, Norway, Portugal, Sweden and Switzerland). Business in these markets will transfer over the coming months, subject to compliance with local law.

This will increase Bing’s market share by 1.2%, which doesn’t sound like a huge amount although it would bring them up from about 20% of the US search share to 21%…. still quite small compared to Google’s 64%.  Curiously though, AOL’s search share rose by .1% between April 2015 and May 2015.

One definitely has to wonder if Yahoo was ever in talks with AOL, with how aggressive Yahoo has been over the past year in order to become the default search – as evidenced by their recent Firefox default search and Java update partnerships.