I'm not sure I can whole heartedly endorse the ROI/business case approach to gating innovation. The reality behind innovation is that true innovation is almost impossible to associate with a valid and reasonable business case and rigorous ROI forecast. That's sort of the nature of an innovation -- something completely new. I also see what and how Amazon manages innovation and do not believe that the business case approach is a primary tactic. Of course, with seemingly inexhaustible capital and resources, Amazon becomes a model-breaker under any circumstances. Still, it may behoove us to think of innovation as requiring an innovative set of management principles.