However, parody is not a defense to infringement per se, but rather an argument that there is no likelihood of confusion—a necessary element of infringement—because consumers will know that the parody is a joke. A parody, though, must make fun of or criticize the trademark or its owner; using a trademark to make fun of something else is not a parody. Thus, to be a parody, Canned Unicorn Meat must be meant as commentary on THE OTHER WHITE MEAT or the NPB. If Canned Unicorn Meat does not qualify as a parody, ThinkGeek may face liability for infringement or possible dilution of the NPB’s famous mark.The authors state the formal rule (and one that works well as a first cut, no pun intended, before we start to take the First Amendment into account), then immediately ignore that they have done so. That is, infringement liability depends on confusion. No confusion, no infringement liability. Parody is just one reason there might be no confusion. So is satire. So is the nonexistence of unicorns.
Forget the literary theory terminology. (Or pay more attention to it! Contrary to legal caricatures, literary theory has multiple perspectives on parody, almost none of which rigidly distinguish parody-as-commentary-on-a-single-work from parody-as-commentary-on-culture, which makes a fair amount of sense given that (a) different people see different types of commentary in the same thing and (b) works that inspire parody happen to be part of a broader culture. I adore Justice Souter, but that parody/satire divide in Campbell was not sufficiently qualified, even though he did try, in a footnote.) Like too many people considering parody and satire post-Campbell, the authors of this post have made the logical error of denying the antecedent: a successful parody isn't confusing, therefore something that isn't a successful parody is confusing.
And yes, I know that the post doesn't say this outright, since it only concludes that ThinkGeek "may" be liable. I consider that statement, in context, misleading. Suppose there's no commentary on pork. Do you think that the pork folks have partnered with ThinkGeek to sell you unicorn meat? Okay, then!