The FTC's Rule of Reason for Limiting Trade

The rule of thumbs that has emerged first in England and then in the United States has been remarkably common and remarkably stable. But it's not all that different from the situation with patents and copyrights where essentially if somebody can use somebody else's patented device free of charge, he can outcompete the inventor by virtue of being able to charge a lower rate. And so what you're trying to do is to figure out how you balance these two things off.