Denny’s Marina Inc. filed an antitrust action, described more fully below, against various defendants: the Renfro Defendants (Renfro Productions Inc.; Indianapolis Boat, Sport, and Travel Show Inc.; and individuals connected with those firms), CIMDA (the Central Indiana Marine Dealers Association), and the Dealer Defendants (various boat dealers that competed with Denny’s in the sale of fishing boats, motors, trailers, and marine accessories in the central Indiana market). The Renfro Defendants operated two boat shows each year, one in the spring and one in the fall, at the Indiana State Fairgrounds. At the time of the litigation, the spring show had occurred annually for more than 30 years and was one of the top three boat shows in the United States. It attracted between 160,000 and 190,000 consumers each year. The fall show was a smaller operation that had occurred each year since 1987. Numerous boat dealers participated in the two shows. Denny’s participated in the fall show in 1988, 1989, and 1990. It participated in the spring show in 1989 and 1990. According to allegations in the antitrust complaint Denny’s filed, Denny’s was quite successful at each of these shows, apparently because it urged customers to shop the other dealers and then return to Denny’s for a lower price. 

After the 1989 spring show, some of the Dealer Defendants began to complain (according to Denny’s) to the Renfro Defendants about the sales methods used by Denny’s. In addition, Denny’s alleged, the Dealer Defendants spent a significant part of a CIMDA meeting venting frustration about similar sales tactics used by Denny’s at the 1990 spring show. Denny’s also asserted that the Dealer Defendants’ complaints to the Renfro Defendants escalated, and that as a result, the Renfro Defendants informed Denny’s after the 1990 fall show that Denny’s could no longer participate in the shows. Denny’s claimed that the defendants’ conduct amounted to a conspiracy, prohibited by Sherman Act § 1, to exclude Denny’s from participating in the boat shows because its policy was to “meet or beat” its competitors’ prices at the shows. What standard per se or rule of reason governed the court’s analysis when it decided the case? Why that standard?