Publishing a SharePoint hosted app

Hi,

I have an app to publish to Microsoft SharePoint app store.

I want to know how trial version works?

Do I need to do something about it or Microsoft takes care of it?

e.g. Trial version of the app will expire after 15 days and after that users need to pay for it if they want full version otherwise the app shouldn't work.

Please point me in the right direction.

Thanks,

Raviraj