Peter Deptula owns a federal trademark registration on “Surfvivor,” an amalgamation of the words “surf ” and “survivor.” Deptula has used the Surfvivor mark for a significant number of years on his many Hawaiian beach–themed products, which include sunscreen, T-shirts, and surfboards. Deptula’s mark consists of the term “Surfvivor” in block or cursive writing, often accompanied by a stylized graphic such as a sun or a surfer. Deptula has advertised his products on local television and radio shows, on his Web site, and at local trade shows. Surfvivor goods are primarily sold in Hawaii through a local university, a drugstore chain, military outlets, and Hawaiian branches of major retailers. Deptula would like to expand Surfvivor’s out-of-state presence, but has not made firm plans to do so. Several years after Deptula coined the “Surfvivor” name, the CBS television network and a television programming organization known as Survivor Productions began broadcasting a reality television show called Survivor. The Survivor program deals with the experiences of competitors who seek to survive in extreme outdoor conditions. The show has been a viewer favorite. Survivor Productions created a special Survivor logo for advertising and marketing purposes. As with the Surfvivor mark, the Survivor mark is emblazoned on a wide range of consumer merchandise, including T-shirts, shorts, and hats. The Survivor mark consists of the word “Survivor” in block script. It is often accompanied by the words “outwit[,] outplay[, and] outlast,” or is superimposed on a stylized graphic suggesting the location of a particular series. When Survivor’s producers began their use of the Survivor name and mark, they were aware of Deptula’s Surfvivor mark. After Survivor began airing on television, Deptula encountered a few persons who wondered whether his business was sponsored by the entities that produced and aired the television program. One retailer and one customer mistook Survivor sunscreen for Deptula’s product, and one trade show attendee thought that Deptula’s business was endorsed by Survivor’s producers. Survivor Productions and CBS never received any complaints from confused customers. A survey commissioned by Survivor Productions revealed that fewer than 2 percent of more than 400 sunscreen purchasers were confused by the two marks. None of Deptula’s customers returned any Surfvivor goods because of a mistaken belief that the goods they purchased were produced or endorsed by the producers of Survivor. No merchant stopped doing business with Deptula on account of confusion between the product lines. Deptula filed a trademark infringement lawsuit against Survivor Productions and CBS on the basis of the facts set forth above. The federal district court granted summary judgment in favor of the defendants. Did the court rule correctly?