The current research included 19 cases of innovation failure from the 21st century. Obvious areas of expansion include increasing the number of cases and examining the historical record of innovation failure. Expanding the number of cases will allow for verification and expansion of the current and preliminary five categories of innovation failure and possibly for creation of a category hierarchy in which main categories of failure are subdivided into variants or subcategories.
Figure 5 illustrates example subcategories for the "no market demand" failure root cause. Although Juicero, Sedasys, and Google Glass failed due to a lack of market demand, there were significant differences across these innovations with respect to how demand played into their failure. In the case of Juicero, once the product's value proposition became clear to the public, its demand disappeared completely. Consumers were unwilling to spend $400 for a machine to squeeze juice from a bag. Genuine demand existed for Sedasys—replacing expensive anesthesiologists with a machine is a compelling proposition. Its narrow use case made it uneconomical, however, and so demand could not be sustained. Finally, Google Glass found no demand among its original consumer market, but its capabilities allowed for a pivot into new uses. Similar subcategorization is likely with other failure categories and would help with understanding the nature, patterns, and causes of innovation failure.
Examining historical cases of innovation failure would expand the sample and also help identify any trends in the causes or patterns of innovation failure over time. In addition to exploring whether the raw root causes for failure have shifted over time, it would also be interesting to know if there have been other changes to the patterns of innovation failure. For example, has the length of time from market introduction (launch) to when an innovation is removed from the market changed? It may have shortened as firms embrace the virtues of failing fast. On the other hand, anecdotal arguments indicate that many startups spend their venture capital even after their innovations seem destined to fail. More cases, and more cases over a longer period, would help answer such questions.