Fair Use: Factor 4: Market

The effect of the use upon the potential market for or value of the copyrighted work.

If the use of the content in your work will take away income from the original work’s format, it is less likely of consideration for fair use. A better situation would be if your work will either cause no effect on or will increase the potential market for that work.

The potential market has become an increasingly important factor in recent court decisions such as Hachette v. Internet Archive. In this case, actual and potential market harm played a role in the judge's interpretation of the other three factors, as well.