If you want a plain English description of why Facebook just bought Microsoft's Atlas ad server, then head over to AdExchanger.
In short, it's about world domination, Facebook ads product director Gokul Rajaram tells the site.
Atlas lets Facebook offer three things:
1. Advertisers will be able to directly compare Facebook advertising results to non-Facebook advertising.
2. Advertisers will be able to compare desktop vs. mobile advertising.
3. Using Facebook's pacts with Datalogix and Nielsen, advertisers will be able to compare Facebook advertising vs. traditional offline advertising. Even TV.
When asked, "Do you want marketers to use Facebook as the hub for all online advertising, and eventually offline as well?" Rajaram gave a two-word answer:
"You're right."
(He also elaborated that it was also about measurement, and that it would take a while for Facebook to integrate and build out Atlas into the tool Facebook but wants it to be.)
The move places Facebook firmly in competition with Google. AdExchanger noted that Google does not participate in either Facebook's FBX ad exchange or offer Facebook in its search ad results, preventing comparisons between Facebook and Google ads results.