A rapid prototyping/launch workflow can certainly help with figuring out which product to focus your energies on. As Kyle puts it:
There’s nothing more fulfilling than creating something out of nothing, and in my opinion there is no better time to transform yourself into someone who can produce something from a mere idea. It doesn’t have to be perfect, or even refined. The ability to create a working prototype of an idea is invaluable. It’s not a mockup, it’s not a powerpoint deck, it’s a real, living, breathing thing that real users can interact with now. If you’re a developer or designer but lacking in the opposite discipline, what are you waiting for? You could be hacking on a cool idea as we speak. If you’re a business guy/woman, or “ideas person”, why spend any more time relying on other people** to build your ideas?