The concept of Messenger becoming a second homescreen for the smartphone is an interesting one. Suddenly their decision to separate Messenger from Facebook on mobile makes a lot more sense. If you think of Messenger as a different type of interface, I think the value-add are the limitations it places on providers: services have to be primarily text-based and updates will all arrive as nested within one push notification (at least on android). Plus, as the analysis mentioned, the threading, logs and identity functionality is built-in. It's almost like having a terminal window for a bunch of rigid functions that works in plain English and anyone can get to grips with.

Now I'm thinking about a parallel universe where text-based interfaces never went away...