Target markets refer to specific groups of consumers that share common characteristics and needs. To be an effective target market, the group must be sizable, reachable, and measurable. Target markets influence a company's marketing strategy and concepts. For example, Sprint targeted college students by sponsoring a college football game. Coca-Cola targeted mothers by sponsoring the Olympics. Niche marketing involves targeting very specific consumer needs not met by other companies. Lululemon found success targeting female athletes with yoga clothing. Competitors then tried to enter this niche market. Sports Illustrated has found continued niche market opportunities targeting sports fans.