But this advice only really applies to projects where you create every service and layer. If you want to incorporate a 3rd party service, or want to allow your

But this advice only really applies to projects where you create every service and layer. If you want to incorporate a 3rd party service, or want to allow your service to be used by others, you need some sort of common format. JSON isn't the most efficient, but it gets a lot of exposure from being a first class citizen of the web. Msgpack is good if you want efficiency. But you need something if you want your program to communicate with others.