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).
The last time Microsoft provided information on the number of users who installed Windows 10 on their devices, be they PCs or tablets, was in January, when it revealed that the Windows Insider program had a total of 2.8 million members, 60,000 of which were said to be running the phone preview.