Why should I sell or share an idea with a business partner?
An NDA may be a good idea if this has truly the potential to be big. If someone is already your business partner then I would think you should be able to share ideas freely between each other. If not you have big issues in this partnership.
Ideas get better then they are exposed to criticism. Welcome this. Ideas get so much better when the idea has been collaborated on. The power of 2 people improving an idea is an exponential improvement.
