For more details and background information, read Liz Gannes article below (last link). Looks like Facebook is mainly interested to hire mobile developers.
Spool :: We started Spool to make content easy to consume on a mobile device. To accomplish this, we built some very sophisticated technology and developed a deep expertise in mobile software development. We firmly believe that solving these problems will be increasingly important as the world accesses the Internet primarily through mobile devices. We are proud to announce that today we will be pursuing our vision as a part of Facebook.
Continue to read blog.getspool.com
HT: Liz Gannes, AllThingsD