THe ultimate question in the back of every entrepreneur launching a new product mind is whether people would buy their product.
They are not sure of customer validation.
They are also not sure if they are solving the problems the way they should.
The best way to solve this dilemma is to create prototypes of your product and go to your potential customer and ask them whether they will be willing to pay for it.
Let them have a feel of what it will look like and how it can help them solve their problems or achieve their goals
Steemit is a great example, 
when you have a long list of customers who are lined up to be the first to buy your product or utilize your service, then you are unto something.