Microsoft’s Bing division will provide search and search advertising capability for AOL’s portfolio of websites for the next 10 years, Microsoft announced today in a blog post. Previously, Google provided these services for AOL.

As a result of the deal, sales and trade marketing employees will go from Microsoft to AOL, whose sites include Engadget, Huffington Post, and TechCrunch. Bing-powered search will go into effect on January 1, according to a statement from AOL.

Further, AOL will sell display, mobile, and video ads across Microsoft’s websites in nine countries.

Meanwhile, AppNexus will “become our exclusive programmatic technology and sales partner” in 10 countries, Rik van der Kooi, Microsoft’s corporate vice president of advertiser and publisher solutions, wrote in the blog post. Business will move from Microsoft to AppNexus in the months to come.

Bloomberg originally reported on the news, saying around 1,200 employees would be affected, but VentureBeat has heard from a source familiar with the matter that the number will be between 500 and 1,000.

The takeaway with this news — and the news earlier today about Bing mapping assets and employees going to Uber — is that Microsoft is doing less in some markets, in order to place more emphasis on markets that are more strategically important.

Programmatic advertising and display advertising were not specifically cited in the sweeping email that Microsoft chief executive Satya Nadella sent to employees last week. Here’s what he did say: “We will need to innovate in new areas, execute against our plans, make some tough choices in areas where things are not working and solve hard problems in ways that drive customer value.” The offloading of as many as 1,000 employees could certainly be called a “tough choice.”