The document discusses different levels of market segmentation, ranging from full market coverage targeting the entire market to individual marketing targeting individual customers. The possible levels include full market coverage with either differentiated or undifferentiated marketing, multiple segments targeting selected subsets of the market, single segments focusing on one market segment, and individual marketing targeting individual customers. Full market coverage aims to serve all customer groups but is only feasible for large firms. Multiple segments diversifies risk by selecting some market segments to target.