From the previous chapter we know that sustainable banking with poor customers is possible. But the ultimate test of any institution is not whether it exists or sustains itself, but whether it manages to do something useful. Do the institutions considered here pass this test? In this chapter we consider what influence experimental banking institutions have had on technology (using that phrase to include employment and all other factors of production) and on incomes; in Chapter 5 the focus is sharpened to examine how the impact on incomes and employment divided between rich and poor, and thence the impact of the schemes on poverty.