Clorox (defendant) produced and sold Combat, a bestselling roach-bait insecticide. United Industries (United) (plaintiff) manufactured and sold a new competing product, Maxattrax. United released a television commercial that directly compared Maxattrax with another roach-killing product that was generically labeled but resembled a Combat package. The commercial stated that Maxattrax killed roaches in 24 hours, but implied that the other product did not. United sought a declaratory judgment that the advertisement did not violate the Lanham Act’s false-advertising provisions. Clorox counterclaimed, alleging that the commercial did amount to false advertising. Clorox filed a motion for a preliminary injunction against the commercial. The district court denied the injunction, and Clorox appealed.