Some magnet schools have a competitive entrance process, requiring an entrance examination, interview, or audition. Other magnet schools select all students who apply or use a lottery system, or a system combining some elements of competitive entrance and a lottery.
As of February 2016, WhatsApp had 1 billion monthly active users, up from April 2015 when the company announced over 800 million MAU. The company's growth in India is also pretty impressive at around 5 million additional MAU per month (60M in Aug '14).
What does Facebook want WhatsApp for? Facebook has a messaging app, Messenger, but it is second to WhatsApp in popularity, so the acquisition vaults Facebook to the No. 1 spot. It also gives Facebook 450 million or so phone numbers, valuable information to have for an ad-based business like Facebook. Facebook CEO Mark Zuckerberg, in a statement on the deal, said that WhatsApp will boost the Internet.org effort to increase Internet access around the world.