The process of diffusion is the main subject of many researching works. Although there are many definitions of above mentioned process, all of them concern physical expansion of some objects taking place in specified environment and well-defined time. The article concentrates on weight of market diffusion of the innovations observed by economics. The role of this process is very wide considering macro- and microeconomic influence. Furthermore there are also other aspects of market diffusion, i.e. social, ecological, political and so on.