That has to be one of the most frustrating UI patterns out there, clicking a button and not knowing whether it will do what it says or say "haha, nope!". It's b

That has to be one of the most frustrating UI patterns out there, clicking a button and not knowing whether it will do what it says or say "haha, nope!". It's bad enough when apps do this to try and persuade you to upgrade to the pro version. What you want to know is not just whether people click the button , but whether having a certain feature available changes the way that people actually use your application.