Surprisingly, managers often do a poor job of identifying potential competitors because they tend to focus on only two or three well-known competitors with similar goals and resources. Historically, Coke and Pepsi spent more time keeping track of each other than they spent on other competitors until they each started losing ground to start-up energy drinks, bottled water,and fruit juices. Likewise, Hoover, Dirt Devil,and more recently, Oreck competed fiercely in the market for vacuum cleaners. When Dyson entered the market with its radically different vacuum that developed and maintained significantly more suction power, the company garnered 20 percent market share within its first months on the shelves. Only then did Hoover and Dirt Devil design their own bagless vacuum.