The name of Coo's business suggests the stock exchange. However, it seems to function primarily as an intermediary between mail-order pigeon firms (such as the J.C. Pigeon Company) and their customers. Bert imagines a triumphant visit to the Pigeon Exchange to pick up his twelve dozen pigeon eggs. Bill N. Coo's name is a pun, based on the common phrase "bill and coo" to describe the mating rituals of birds, especially pigeons and doves.