As readers may already appreciate, to prove trademark infringement, a plaintiff has to meet two equally important requirements.

First, it must demonstrate that a defendant's mark is likely to cause confusion with the plaintiff's own. Second, the plaintiff must be able to prove that it used its own mark before the defendant used its mark.

Often, when determining whether to sue for trademark infringement, would-be plaintiffs obsess over the confusion issue, but they often overlook the matter of priority of use. And in truth, priority of use is typically a rather boring aspect of an infringement examination. Establishing likelihood of confusion can be the more complex and therefore more interesting aspect of a trademark infringement claim, perhaps explaining why the simple question, “Did the plaintiff use its mark before the defendant used its mark?” is passed over.