When fishermen from the Indian state of Kerala are done fishing each day, they have to decide which of an array of ports they should sail for in order to sell their catch. Traditionally, the fishermen have made the decision at random–or, to put it more charitably, by instinct. Then they got mobile phones. That allowed them to call each port and discover where different fishes were poorly stocked, and therefore where they would be likely to get the best price for their goods. That helped the fishermen reap a profit, but it also meant that instead of one port’s being stuck with more fish than could be sold while other ports ran short, there was a better chance that supply would be closer to demand at all the ports. The fishermen became more productive, markets became more efficient, and the Keralan economy as a whole got stronger.
My favorite part, however, is the one that you usually don't see in articles about Social E! and appropriate tech. It's the sober admission that you can't help everyone at the same time. Economics isn't a zero-sum game, but often, when someone benefits from something, someone else is disadvantaged anyhow. There are many counterexamples to that generalization and many more ways to minimize the effect, but it's still there more often than not. As we help thousands of people leap the digital divide, we still leave others behind.*
It would be a mistake to see Cam and technologies like it as a panacea for the problem of underdevelopment. While it's easy to become infatuated with the promise of microfinance and small-scale entrepreneurship, it's also easy to overestimate how much influence these things can exert on developing economies, which often face structural problems that won't be solved by making local markets more efficient. And it's also the case that, in the short run at least, the arrival of new technologies can widen the gap between the prosperous and the struggling: if you're buying more from the Cam-equipped farmers, you'll probably buy less from the non-Cam-equipped ones. In other words, not everyone will win.
*That's okay. We don't have to save the world ourselves. That's why there are another 6,602,224,174** of us.
**(according to the CIA Factbook this month)