There are only two ways you can make meaningfully make money. You can either find out what people want and work out a really clever way to make it or you can work out what you can make and find out a really clever way to make people want it. I think the most successful goods are a combination of the two, for example, (something totally unwanted becomes desirable due to the workings of marketing) - at the other extreme you have commodity goods that people want at the beginning and your job is simply to provide them as cheaply and efficiently as possible. Very few things lie at those extremes, most things are a combination of essentially understanding human needs and also understanding how you can present what you make in a way that makes it likeable. I think most really successful inventors and entrepreneurs are also great showmen and salesmen. For example, Steve Jobs, Elon Musk, Thomas Edison, they are people who not only know how to make clever things, but they also know how to sell them.