This document summarizes the key steps in market segmentation, targeting, and positioning. It outlines 6 steps: 1) Identifying bases for segmenting the market, 2) Developing profiles of resulting segments, 3) Developing measures of segment attractiveness, 4) Selecting target segment(s), 5) Developing positioning for each target segment, and 6) Developing marketing mix for each target segment. It then discusses various bases for segmenting consumer and business markets, as well as international markets. The key requirements for effective segmentation are that segments must be measurable, accessible, substantial, and differential.