Market validation. It comes in many forms and shapes! And often it's overlooked. Used as an excuses: Henry Ford, Steve Jobs.. they didn't listen to customer, because customers don't know what they want! Sure, true, to an extent.
Especially when it comes to surveys and asking the customer, because deceiving others is very much human nature - even when done subconsciously, without bad intent!
Yet, developing a product or service for your business without getting feedback or the proper market validation, in whatever way that might be, is a big no-go. Sure, you can get lucky and make it through, but in most cases, you'll waste a lot of time, energy, effort AND money.