After weeks of speculation and leaks, Facebook announced it will buy the Atlas Advertiser Suite away from Microsoft. The Seattle-based Atlas team will stay put, but Facebook plans to invest in back-end scaling and better measurement to help advertisers “close the loop” and understand how their spend earns them money. Discussions between the tech giants were first reported by Business Insider in December. AdAge has been closely following the story and provided many leaked details, including that Microsoft had been aggressively searching for a buyer and that the price was to be less than $100 million, following previous bids in the $30 million to $50 million range. Microsoft originally acquired Atlas through a $6.2 billion purchase of its parent company aQuantive, which also owned Avenue A / Razorfish and DRIVE Performance Solutions. Now the acquisition is official, though no price was announced.