This study investigates self-governance within business-to-business (B2B) in the digital knowledge economy. To do so, we elicit the engagement of healthcare professionals (HCPs) and medical science liaisons (MSLs) with “for-profit social media technology” (FPSMT) in e-detailing. Using data from 23 in-depth interviews with HCPs (physicians and pharmacists) and MSLs in Thailand, we show that e-detailing fosters self-governance as a practice. The data identify how FPSMT, as privatized social media managed by large firms, represents a tool for self-governance that is articulated by expert professionals along three cognitive frames: aspiration, regulation, and responsibilisation. Through FPSMT, professionals in highly regulated B2B ecosystems engage in self-governance practice to develop pooled views that are influenced by personal and collective rules. The perspective on self-governance as a practice that is offered allows to understand how B2B network governance rely on professionals’ engagement to foster aspirations for the collective agenda, beyond the narrow pursuit of sales’ objectives.