Attrition is one of the most important challenges faced by Professional Associations like the Project Management Institute (PMI). According to publicly available data, 90,000 members joined PMI in 2005. In the month of April 2006 alone, 33,751 new members were added, which leads to the logical conclusion that the PMI membership must have grown by over 115,750 during the period 2005-2006. However, records show that the growth has been by only 70,000. PMI’s reported growth of 5% would have been much higher had it not been for their attrition of 23%. Similarly, ISACA’s growth during 2014 dropped to 4% due to their attrition of 19%. In this paper, we combine the social identity theory and communication ecology theory to propose a Social Identity Theory (SITPA) for professionals. We argue that by leveraging the social media, Voluntary Professional Associations (VPAs) can provide “value” to their members, increasing their retention rates.