If you’re not familiar with Steve Blank, start here:
The Principles of Lean
“No business plan survives first contact with customers.”
On Acting on Customer Discovery
If you’re going to go out and discover whether customers like your idea or not, this is not an outsourceable problem. The founders need to do this. Particularly, the people capable of changing strategy need to be the ones hearing good news and bad. … Getting feedback from customers is the most valuable thing you will do as entrepreneurs. It is not outsourceable.
The thing is to think as much in terms of developing customers as developing products. Once you’ve got the basic idea, watch all of this (long) video: