Normal procedure in attempting sale of a valuable idea is for the claimant to offer his idea for sale to the recipient who usually will refuse to buy it until disclosure. Then, after disclosure, the recipient may or may not promise to pay for the idea if he uses it. In either case, the recipient may use the idea later, perhaps in a modified form, and refuse to compensate the claimant.
Homer C. McRae, Disclosure of Specific Types of Ideas: Misappropriation, 9 Clev.-Marshall L. Rev. 29 (1960)