After running an advertising campaign intended to increase sales of its line of dishwashers, an appliance store notices that consumer WTP for its dishwashers seems to have increased. However, the store has not captured any market share from its competitors. Which of the following might explain this outcome? a. The advertising campaign focused on negative features of competitors' dishwashers rather than the positive features of the store’s own product. b. The advertising campaign focused on the advantages of owning a dishwasher, but did not mention the store’s specific brand of dishwasher. c. The advertising campaign alerted consumers that the store was having a major sale on dishwashers, without emphasizing the desirable features of the dishwashers. d. Dishwashers exhibit network effects, and the store is therefore operating in a "winner-take-all" industry.