Product Demand Fit
Much is written of “Product Market Fit” however I prefer to use a different term: Product Demand Fit.
They mean the same thing, but the later makes it clear that you are hunting for demand, hunting for something people want.
The higher the demand for a product/service the less good a product/service can be and still meet the demand. If you are selling water in the desert you are not going to be asked if you have flavoured water.
These phrase leans into other areas too - like over-serving customers. Should you sell flavoured water in the desert? It will cost you more to make, but will the customer value this? Over-serving leaves a gap for a competitor to enter with a worse product universally - but one that better fits the needs of the user.
One definition of Product Market Fit is if 40% or more people say they would be disappointed if your product/service disappeared. This still applies for Product Demand Fit.
A good market pulls the product out of a startup - Marc Andressen