If your book hasn't made you rich in the first 14 years after publishing, I'm sorry, audience just isn't that into you.
(I am aware movie deals can languish for many years before finally landing a deal, and with 14 years studios could just wait you out and there's no incentive to write a script anymore, but copyright should be 14 years after publishing right? And movie scripts are not generally published before they get made into a movie, if ever.)