It has been widely recognised that Building Information Modelling (BIM) is one of the most critical innovations that represents a technological and procedural shift within the Architecture, Engineering and Construction (AEC) industry. BIM represents a methodology to manage the building design and project data in digital format throughout the building lifecycle. Although the benefits of BIM seem evident, its diffusion within the AEC industry has been slow and its current adoption has not been to its full capacity. To shed additional light on the diffusion of BIM, the research presented in this paper was aimed to examine and analyse the current perceptions of AEC professionals regarding their experience with BIM, which are publicly shared on a popular social network for professionals - LinkedIn. The research adopted Everett Roger's Diffusion of Innovation (DOI) theory as a conceptual framework to guide the analysis. The analysis was performed using a qualitative technique through NVivo 10 software to analyse 45 discussion threads, retrieved from one of the BIM-specific discussion groups, for themes and concepts relevant to the diffusion of BIM. The findings revealed a number of key insights into the critical issues impacting the diffusion of BIM currently faced by the professionals within the AEC industry. These include: the difficulty for companies in adjusting their existing workflow and culture to accommodate the adoption of BIM in such a way that they can exploit its full benefits; the misconception of BIM that led to users' disappointment and eventual abandonment of BIM; and the implementation of BIM for short term gains rather than long term investment.