104 Iowa L. Rev. Online 105 (2019)
Back in 2007, the Iowa Law Review published a dialogue between Graeme Dinwoodie and Mark Janis, on the one hand, and Stacey Dogan and Mark Lemley on the other. The topic was "trademark use," and the question was whether such a doctrine really exists. Dinwoodie and Janis said no-that while only commercial use of a trademark can be considered infringing, there is no threshold requirement that the plaintiff prove that the defendant has used the mark in some particular "trademark" way. Dogan and Lemley said yes—that some "uses" of a mark simply don't trigger liability, and a court needs to determine, as a threshold matter, whether the defendant has used the mark "as a brand." I was not a disinterested bystander on this question. When I wrote, responding to both papers, I argued that trademark law does, and must, impose liability for only particular kinds of uses of a mark—uses "as a mark." But because "trademark use" can only be determined from the perspective of consumers, I argued, the question of whether a particular use qualifies inevitably collapses into the likelihood of confusion analysis (and therefore isn't a separate, threshold question.)
In the years following the trademark use debate, courts largely sided with Dinwoodie and Janis (or, I think more accurately, with me)-rejecting the contention that trademark use is a separate, threshold requirement.
In fact, trademark use is everywhere in trademark law-in cases dealing with acquisition of common law rights, in priority disputes, in infringement cases, and in cases involving a variety of defensive doctrines. And, as Alex Roberts details in her excellent article Failure to Function, even more pervasively in the registration context.
The problem is that trademark use is only at issue when it's lacking; when it's present, it's invisible. In this respect it should be no surprise that the Trademark Office has no real theory of trademark use, only a rule that prohibits registration when the claimed mark fails to function as a mark. Trademark use is also primarily a functional consideration; an indicator has been "used as a mark" when, by virtue of its use, consumers are likely to regard it as source-indicating. Because that is an empirical question for which the Trademark Office typically has no empirical evidence, failure to function has a sort of "know it when you see it" quality.
Mark P. McKenna,
Trademark Use Rides Again,
104 Iowa L. Rev. Online 105 (2019).
Available at: https://scholarship.law.nd.edu/law_faculty_scholarship/1436