Adoption of Innovations reviews the Bass model and its new generation extensions as well as the alternative approach - the threshold model, which analyzes an individual's decision whether, and to what extent, to use a new technology given economic conditions. The authors show that the threshold model has a notable advantage in incorporating marketing tools that are targeted to and/or aim at reducing risk. This monograph describes the two models. It shows how they relate to each other, and then discusses how marketing tools, and in particular marketing tools that are designed to reduce risk, can be incorporated into each of the two models.