Popular messaging apps like WeChat and Line are slowing demonstrating the power of messaging apps.
In Japan, the Line messaging app is allowing users to book taxi and look for jobs directly within the app. The user doesn't have to leave the app to use the different services. WeChat already provides banking services in China.
Both these apps showcase the power of messaging apps as the new "web browsers" for the smartphone generation. Facebook and Twitter popularize the notion of the social web, where people would use their social network to obtain information (ie asking your friends for advice, posting a message for the world to see, etc). Messaging apps are taking it to a whole new level by combining the social web via contacts in your messaging apps and integrating the services directly. From a user perspective, they don't have to exit the app, which is currently the case for most actions right now on your smartphone (a specific app for a specific service). Messaging apps can do away with that all together.
How is it different from a web browser? Well, a web browser lacks the social element (no contacts and no messaging) and so while users can use the web browser to complete their desired actions, they aren't able to use the social/messaging element.
And let's be honest, what did we get a phone for if not to talk/chat/communicate with our friends? So it seems that messaging apps are the ideal "web browser" platform for smartphones. It's only a matter of time until all services are integrated directly in the messaging apps.
The current state of messaging apps is similar to the early days of web browsers where people are trying to figure out how to best maximize the screen space and what services to provide. Eventually, web browsers offer all these different extensions and tools that augment its capabilities and personalized it for its user.
It shouldn't be too long for messaging apps to reach that stage.