In July 2015, Microsoft announced its write-off of its Nokia handset business (acquired a year earlier) and its withdrawal from the smartphone market. Its Windows Phone operating system had a 1% share of the smartphone market and there were about 290,000 Windows Phone apps (compared to 1.6 million for Android and 1.3 million for the Apple iPhone). How do the dynamics of platform-based competition (see Strategy Capsule 4.1) help explain Microsofts failure in the market for smartphones?