by Patrick Appel
Philip H. Howard provides a visual:
Three firms control 89% of US soft drink sales. This dominance is obscured from us by the appearance of numerous choices on retailer shelves. Steve Hannaford refers to this as "pseudovariety," or the illusion of diversity, concealing a lack of real choice. To visualize the extent of pseudovariety in this industry we developed a cluster diagram to represent the number of soft drink brands and varieties found in the refrigerator cases of 94 Michigan retailers, along with their ownership connections.
A much larger version of the graphic is here.
(Hat tip: Flowing Data)