Nearly 3.2 billion people around the world, many of whom live on less than $10 a day, have been excluded from formal markets. They are often referred to as the “base of the pyramid” (BOP). Yet, they defy simple homogeneous characterization. The lowest third of this group, in terms of income, focuses mainly on subsistence and will require support to rise above poverty. The top third, about a billion people, are beginning to generate significant discretionary income; still, they too are forced to resort to substandard, and often more expensive, formal markets. Together, they are brimming with productive and entrepreneurial potential, as well as latent demand for products and services.