This study investigates broadcast search within the context of intra-firm, cross-community online threaded discussions. For a knowledge seeker, mobilizing external contributors―those situated outside the focal problem domain―offers access to diverse expertise and novel perspectives. However, empirical evidence suggests that broadcast search-initiated discussions often yield inconsistent outcomes. Drawing on the theoretical lenses of technical marginality and network structure, this study develops a contingent model specifying the structural conditions under which contributors effectively resolve the tension between knowledge diversity and knowledge integration. An analysis of 195 broadcast search-initiated discussions within a global enterprise reveals that the most effective network configuration is characterized by sparse intra-group connections within internal and external contributor cohorts, coupled with dense inter-group connections between them. This specific architecture facilitates access to nonredundant knowledge while ensuring its successful integration, thereby enhancing the seeker’s learning―conceptualized as the cognitive reframing of a problem through newly synthesized perspectives.