Today, mobile devices like smartphones and tablets are omnipresent in many parts of the world. They are used for private and business activities. The effects of mobile business are discussed more and more in micro-enterprises as well as in small and medium-sized enterprises (SMEs). The question is: Do these devices have an impact on the productivity, flexibility and business processes of companies? The goal of this paper is to develop an explorative model that helps to identify and explain these effects. The investigation is based on a quantitative empirical study conducted among 900 Swiss SMEs. The model is estimated and evaluated using Partial Least Square (PLS) structural equation modelling. The results show that the number of mobile devices used and the portion of work carried out offsite have only a low impact on the perceived value of smartphones and tablets. On the other hand, the impact on value is high if mobile devices support business processes and if the variety of information used is high.