If you can answer that question, and make something that they want, you’ll be able to create a product that stands out, gets a lot of media attention, and becomes a bestseller. If you can’t answer that question right now, answer that question. The bestselling products are the ones that solve problems or are the ones that are in high demand. Anything that solves a big problem ends up going in high demand, so it’s best to find out what they want.
If you create something for them, they will buy the product. If you create something for yourself, you’ll only get a few sales. What do they want, and are you in a position to give them what they want?