Then Safaricom had to get its millions of customers to swap out their SIM cards by picking up new ones from their local participating stores.

FORBES: How Africans Shop With Their Cellphones

Generalised subsidies are being replaced with carefully directed ones: for instance, some 1.5m of the poorest families can get a free tortilla ration by swiping cards through an electronic reader at their local tortilleria, where previously the height of technology was the gas-powered tortilla-squashing machine.

ECONOMIST: Mexico