This is a great jujitsu move, and very seductive. Facebook is trying to co-opt the next Snapchat. Yes, the smartphone is a social platform that makes it easy to use multiple social apps, but you still have to get someone over the hurdle of installing the app in the first place, and they have to get all of their friends to install it too so that they have someone to send to. Facebook is trying to bypass that – you can drop your content straight into the existing Messenger install base (600m MAUs). Now just one person can get a cool app and send messages to their friends even if their friends don’t have it, and if it’s cool enough they can tap on the link and install it too.
Exactly the reason why I’m thinking of making my next side project a part of Facebook messaging. However the user experience of using 3rd party apps in Messenger is still relative bad. It’s funny that you have to tap a few times before you get to a decent gifs on giphy. Why not be like hipchat? Where I can easily do a /giphy happy and it will randomly show me a happy gif. I believe that experience will be much better.