In order to gather as much feedback as quickly as possible to validate your sustainable business model, one should create a minimal viable product that is just enough to gather feedback from customers behaviours.
This would help with validating the value hypothesis, and perhaps even the growth hypothesis.
Reference
Ries, Eric. The Lean Startup: How Today’s Entrepreneurs Use Continuous Innovation to Create Radically Successful Businesses. 1st ed, Crown Business, 2011.
Highlights or timestamps
This minimal viable product (MVP) should be as simple as possible and should contain only what is needed to give the customers a realistic experience of how your product would work – just enough to draw useful feedback from them.
— ^e2673d from The Lean Startup