The world's social problems are so complex and so diverse that there will never be a "one size fits all" model for social innovation. This chapter describes what people have learned about the relevance of such variables from the selected inspiring initiatives. It considers how useful they are as parameters to understand whether a given social innovation is best placed to meet its social objectives and bring about systemic change. The measurement of social impact from the exchange networks is somewhat different, partly because they have a very different funding model. All of the cases depend on a series of interactions at the different interfaces between the market, grant, government and household economies. These case studies reveal how social organisations, just as all organisations, thrive on efficiency, transparency and measurable outcomes for sustained growth. There is a growing sector of different types of organisations with an interest in stimulating, supporting and observing social innovation around the world.