One of the most common mistakes new Amazon sellers make is starting a product without knowing if people actually want it. It usually happens when you are excited about an idea, in a rush to start, or treating it as a side hustle. There is nothing wrong with testing, but guessing can be expensive. Before investing in inventory, branding, and ads, ask yourself if this product has an audience, if people are actively looking for it, and if the demand is consistent or short-lived. Validating demand first saves time, money, and frustration.