A slight variation of it is - sell it before building, but let the users know it isn't ready it. Give them a deep discount (50% or more) for their trust. The id

A slight variation of it is - sell it before building, but let the users know it isn't ready it. Give them a deep discount (50% or more) for their trust. The idea is to set a release date, and if you don't hit it, refund the money.