Competitive Strategies for Market Leaders
Suppose a market is occupied by the firms shown in Figure 7.2
Forty percent is in the hands of a market leader, another 30 percent belongs to a market challenger, and 20 percent is claimed by a market follower willing to maintain its share and not rock the boat. Market nichers, serving small segments larger firms don’t reach, hold the remaining 10 percent.
A market leader such as McDonald’s has the largest market share and usually leads in price changes, new-product introductions, distribution coverage, and promotional intensity.
Although marketers assume well-known brands are distinctive in consumers’ minds, unless a dominant firm enjoys a legal monopoly, it must maintain constant vigilance. A powerful product innovation may come along, a competitor might find a fresh marketing angle or commit to a major marketing investment, or the leader’s cost structure might spiral upward.
To stay number one, the firm must find ways to expand total market demand, protect its current share through good defensive and offensive actions, and increase market share, even if market size remains constant.
Dutch 
English