BACnet International commissioned a market research report in 2018 which was conducted by BSRIA and titled "Market Penetration of Communications Protocols." The study indicated BACnet's global market share continued to rise over the last five years and now exceeds 60%. The five year outlook projects continued growth in BACnet adoption with continual improvements to the standard and its integration with technologies, such as IPv6 and web services.
For more information, the study can be found on https://cdn.ymaws.com/www.bacnetinternational.org/resource/resmgr/files/bacnet_adoption_market_resea.pdf