Normally it's a bad idea to allow users to click, or even see, buttons for things he cannot do, but would it be ok as a conversion strategy? Imagine this simple scenario in a marketplace app:
The user cannot publish products before his (billing) account is fully verified. But as a gradual engagement approach, he is allowed to register his products. There's always a "publish" button available to him.
When he finally hits "publish", if his account is not verified, the system takes him to the verification steps, also displaying the reason why he has been redirected. So by the time he finds out the process is longer than he thought, he has already spent time with and seen value in the app.
Is that a valid approach? Wouldn't it be worse if the publish button was replaced by warning text, possibly scaring him away before he plays around with it? And if redirecting is too invasive, perhaps displaying a tooltip or even a modal on click would work better?