What explains the pattern of selective business interest in preferential trade agreements (PTAs) with active campaigning for and utilization of tariff preferences for some trade agreements, but not others? Under what conditions can business advocates of PTA policy mount an effective lobbying campaign to influence policy outcomes (i.e., shaping decisions on who to negotiate with and what to negotiate about)? These are important questions given that analyses of Asian PTAs frequently assign a negligible role to business interests either out of apathy or lobbying weakness. To understand the pattern of selective business lobbying for PTAs, I develop a theoretical model with three main independent variables: venue selection, preference intensity, and advocacy effectiveness, and apply it to the case of Japan to test its usefulness. My model shows that the conditions for effective business PTA campaigning are exacting: loss avoidance, high technical expertise, and influence-seeking strategies that maximize access opportunities given institutional constraints. And yet when these factors align, business interests do influence PTA outcomes. My research shows that the current trend to characterize the agency of PTA proliferation as either state-led or business-driven needs to be re-examined as it is more useful to think about state-society constellations in favor or against PTAs.