In the age of the customer and the increased market for selling experiences rather than sole services, it is really important to understand the journey users will follow. The service/experience you are selling might be just a piece of that whole ecosystem of services, and just a step in the flow, but understanding the whole picture is a key piece to make any app/service successful.
The other day I was reading a Gartner article in where they present this buy/own/advocate Customer journey and I found it really interesting.
Keep this picture in mind when designing your application. If along the way you can tackle each of those pieces, you will not only get customers but also keep them using what you are selling.