Rebel Oil Company, Inc., and Auto Flite Oil Company, Inc. (Rebel) (plaintiffs), brought a claim against Atlantic Richfield Company (ARCO) (defendant), alleging that ARCO had engaged in predatory-pricing practices by selling self-serve gasoline below marginal cost from 1985 to 1989. Both Rebel and ARCO only sold self-serve, cash-only gasoline from their retail stations in the Las Vegas area. Although both Rebel and Arco agreed that the relevant geographic market was Las Vegas, Rebel and ARCO disagreed on the definition of the product market. Rebel contended that the market should be limited to self-serve gasoline, while ARCO contended that the market should be defined more broadly to include both self-serve and full-serve gasoline, because the full-service stations could easily be converted into self-service stations. The district court agreed with ARCO and concluded that the relevant market to assess Rebel’s antitrust claim included both self-serve and full-serve gasoline. Rebel appealed the decision.