Nike is the largest seller of athletic footwear and apparel, founded in 1972. It has a diverse product portfolio including shoes, apparel and equipment for various sports sold in over 160 countries. Nike pursues a strategy of acquisitions of complementary brands and diversification to protect its premium brands and revive struggling brands. It focuses on innovation through R&D, celebrity endorsements, and targeting specific consumer groups through localized marketing. Issues around working conditions at some supplier factories have led to increased monitoring and transparency efforts.