This is a PhD thesis that is ongoing. In this paper the authors investigates how sustainability of BDS can be explained; why some BDS providers succeed while others don’t; what the successful BDS providers do differently from those who are not as successful. Grounded Theory is used and justification for its use is given. Data collection and analysis is still going on. Preliminary findings from the data so far collected and analyzed show that what makes sustainable BDS seems to vary from one individual provider or organization to another depending on the motivates for venturing into the business, the personal attributes of the provider, the business approach that the provider takes and on the prevailing external factors. Furthermore it depends on how sustainability has been defined.