This paper analyzes the structure of retail markets by highlighting the differential pattern exhibited across local markets by two different types of firm organization: chain stores versus stand-alone stores. Data from retail alcoholic beverage industry in California suggest that the number of chain stores is proportional to city size. Further evidence on the sales of establishments indicates that average size of a stand-alone store virtually is invariant to city size, whereas chain stores appear to get larger as city size increases. Theories consistent with these findings are discussed.