The foremost challenge facing marketers today is "proliferation"—complexity brought on by the growing fragmentation of customer segments, the simultaneous demand for both high- and low-end products and services, the declining effectiveness of traditional media, and the sheer number of touchpoints that customers now demand. This collection of articles offers perspectives from McKinsey & Company's Marketing & Sales Practice on how companies must adapt their approach to marketing strategy, execution and organization to profit in a proliferating world