Use APIs to Create your Own Adventure
When I was younger my favorite books were the choose your own adventure. In case you are not familiar with these books the main character is given a choice and you as the reader can decide which path to choose for the character. If you choose path A then you would turn to one page and if you chose path B then you would be taken to a different page.

Choose Your Own Adventure from http://cdn2.hubspot.net/hubfs/2192015/Choose%20Your%20Own%20Adventure.png

When you use APIs you are choosing your own adventure where the applications being built are the adventure. You can have the APIs collect trip data, find better routes with less traffic or find routes with the best waffles. APIs allow you to pull data from multiple sources and integrate readily into application. You as the author can create multiple scenarios for a user with who wants multiple adventures or a single scenario for the single task that the user needs. APIs let you build an endless supply of adventures.