Local business associations can be important mechanisms for stimulating inter-firm cooperation leading to economic growth and development. However, previous research suggests that the unfulfilled expectations of their members can lead to low participation, high membership churn and network instability over time. As a departure from studies that have explored why local associations supply certain benefits and services, this paper draws on an original, demand side membership survey of local business associations to identify for the first time the bundles of benefits sought by members. Two bundles of benefits (instrumental and info-social) relating to thin and thick models of rational choice, respectively, are identified in explaining why firms join and remain part of associations. The relevance of these bundles to members was found to vary with business profile and length of membership, with the value of instrumental benefits reducing over time, whereas the demand for info-social benefits remained relatively stable. The findings have important implications for local strategies for sustaining business networks.