Extensive market segmentation is a relatively recent phenomenon. Until about the middle of the 20th century many firms offered a single basic product aimed at the entire mass market (such as Coca-Cola or Levi jeans). But in recent years many firms—including industrial goods manufacturers and services producers as well as consumer products companies—have begun segmenting their markets and developing different products and marketing programs targeted at different segments. Which environmental changes have helped spark this increased interest in market segmentation? What advantages or benefits can a firm gain from properly segmenting its market?