Answer:
Proprietary License gives you full ownership and trademark/patent opportunites. Open source allows for code donation and a community based development for your app. Generally speaking, if your a private entity creating an app for a client, you'll need the Proprietary Licence, which will allow you to sell the codebase to your client.
If your creating an app for your company as itself, you go either way, sell the license in licensing agreements, or have your companies community contribute and better your app from the inside.
Its entirely based on the agreements you set for the app.