We investigate how IT-capability leads to more interaction business practices, both through inter-organizational systems (IOS) and social media (SM), and how they further lead to marketing effectiveness and firm success. After analyzing the data collected from manufacturers (N=504), we find that (1) IT capability has a significant positive effect on both IOS-enabled and SM-enabled interaction practices; (2) IOS-enabled interaction practice has significant positive effects on both marketing performance and financial performance, while SM-enabled interaction practice only has a significant positive effect on the market performance; (3) both IOS-enabled interaction practice and SM-enabled interaction practice partly mediate the positive influence of IT capability on marketing performance and financial performance; (4) marketing performance partly mediates the positive impact of IOS-enabled interaction practice and fully mediates the positive impact of SM-enabled interaction practice on financial performance. © 2019 Association for Information Systems. All rights reserved.