Ralph L. Woods: An ambitious farmer, unhappy about the yield of his crops, heard of a highly recommended new seed corn. He bought some and produced a crop that was so abundant his astonished neighbors asked him to sell them a portion of the new seed. But the farmer, afraid that he would lose a profitable competitive advantage, refused.
The second year the new seed did not produce as good a crop, and when the third-year crop was still worse it dawned upon the farmer that his prize corn was being pollinated by the inferior grade of corn from his neighbors’ fields.
C.R. Gibson, Wellsprings of Wisdom.