I agree with you that the hold of these apps can be surprisingly tenuous, and the history of desktop IM client switching would bear this out. However, there's

I agree with you that the hold of these apps can be surprisingly tenuous, and the history of desktop IM client switching would bear this out. However, there's also a good argument that mobile messaging was a shift to a new platform (and the inevitable replacement of SMS). There are some fairly resilient network effects, mostly geographically focussed, Whatsapp, iMessage, Wechat. Wechat is just further ahead than the other networks in showing what a messaging platform can develop into, a platform, rather than merely a replacement for SMS. Naturally Wechat has also been sheltered from competition by the great firewall. So Wechat is an indispensable app if you live in China, but in the rest of the world almost no one knows that it exists. You don't only use Wechat to chat with your friends, but also to query your bank balance, pay at McDonalds, and shop online. It's all very weird, because the UX is chat, but if your first computer was a smart phone then it probably feels more natural. Even though the switching costs between mobile messaging apps seem much lower with mobile and notifications (it's easy to have a dozen installed), it still takes a lot to convince all your contacts to install something new. If these apps become platforms that people get used to using to using to interact with their bank or sirline it beomces harder to unseat.. Consider how just a few mobile apps not being available on blackberry or windows phone makes switching to these minor platforms difficult.