This dissertation sheds light on co-operative (co-op) distinctive characteristics that, together with mainstream business features, condition co-ops’ sustainability. We first examine the inter-relationships between internal organization, strategies, and performance. We show that co-ops need to embrace customer-focused strategies (e.g., market and brand orientation) while centering on organizational restructuring that secures member commitment. We then deliver a new comprehensive dashboard for co-op performance assessment that reflects co-op specificities (e.g., accounting for both business and social-membership aspects), advancing the current debate on how to best appraise it. Subsequently, we explore a core co-op threat (i.e., member-customer ostracism) relating to co-ops’ social environment, and develop a diagnostic tool. We also delve into its’ “poisonous” effects, empirically assessing its’ influence on critical membership outcomes, as well as providing an “antidote”. Overall, this dissertation will aid co-op leaders in making informed decisions about organizational and strategic attributes, documenting co-ops’ socio-economic impact consistently, and fending off a core social threat to the central co-op element, the membership.