Of course your business may still fail for a thousand reasons some related to you (management skills), some beyond you (timing and economic cycle). But if no one wants to buy, it is proof that there is no potential - change what you make or go invent something else.
The trouble is that this sales "acid test" is almost never performed soon enough. Innovators waste untold resources on whimsical notions that the world needs X because they thought so and without ever asking anyone if it is true, except perhaps for overly sympathetic family and friends. The genetic make up of the inventor/innovator is to instinctively seek solutions to perceived problems, then develop total belief in the solution found, often with smug disregard for the opinion of the less innovative. Unfortunately, those less innovative folks are the customers that should buy your product (BTW they probably innovate in their domain just as much, just do not appear so to you). Because their focus is elsewhere, almost always they will have different perceptions than you. BUT, if they do not like your offering, your product is crap: beautiful, genial, elegant perhaps, but business-wise it is still crap.
Before investing a great deal of energy developing prototypes, let alone finished products, do yourself a great favor:
1 Get out of your office or garage
2 Look for 10, TEN, not two, TEN prospective buyers of your product
3 Find a way to explain in 45 seconds: what you offer, and its value proposition4 Continue to search until you have found ten that say they would buy whatever you intend to make
5 After TEN people say they will buy at the price you envision, go prototype your product.
6 Then go back to validate with your ten prospects if they would still buy it.
7 If less then ten would, use the feedback to explore design modifications and
8 go back to searching for prospective buyers until you are back to ten
9 Repeat the loop for every prototype iteration
10 If you have less than ten fans or buyers go back to look for more - Remember TEN
Clearly this formula calls for good walking shoes and door knocking stamina far more than an MBA. The latter in fact will give you countless excuses to stay in your office to over analyze your own questionable notions of reality until, eventually failure will lead you to forget the textbooks and fancy formulas codified years ago, then get good sneakers and go talk to customers about what they want NOW.
It is a simple formula: TEN
Oh, and you can bet heavily on this outcome: If you can show your prospective angel investors that you have done this field market research, or better yet you have actually sold something to somebody, you'll be in a class apart from all the funding seekers they see - you will have the beginnings of a proof of market