This paper reports the results of direct observations of language use in two shopping areas in Shanghai, Nanjing East Road and Xujiahui. The data reported in this paper were collected in 2007. In Nanjing East Road, four traditional stores provided a base line for the use of Shanghainese. That base line (60 percent) was compared to a hierarchy of department stores in Xujiahui. The results showed that the store that best matched the base-line data attracted customers representing upper-working class / lower middle class customers. The remaining two stores attracted middle class and upper class customers. In the latter setting, it was found that a certain segment of the customers switched from Shanghainese to Putonghua for the business transaction, an effect this paper linked to the presence of young urban professionals of all backgrounds. The implications of these findings are discussed in the context of speech community theory, and network density, which allows predictions of changes taking place within the dominant language of the Shanghainese speech community.