The benefits of cell phones in emerging markets

Why do cell phones have such an enormous economic impact in emerging markets? What are the economic impacts of cell phones in emerging markets? How big are the economic benefits of cell phones in emerging markets?

The marginal value of cell phones in emerging markets is particularly great precisely because the available substitutes are expensive, slow, unreliable, or just hard to figure out. Whereas in an economy with good infrastructure, cell phones can be replaced with land lines or email, an economy with only cell phones would otherwise have to rely on expensive and slow face-to-face visits, mail, radio air time, and print publications to replace the calls.