To use a competitor's trademark in an ad that is critical of the product would be infringement, since it would be unauthorized use of the name.

Question

Quizplus · Accepted Answer

This can fall under the doctrine of nominative fair use, where a trademark is used solely to refer to the trademarked product itself for purposes such as comparison, criticism, or parody, without suggesting endorsement or affiliation.

To Use a Competitor's Trademark in an Ad That Is