What is the “missed call” market and why does Twitter want in?

Twitter’s acquisition of Bangalore-based ZipDial gives it access to a fairly massive market for “missed call” services, which many phone users in developing countries use as a low-cost method of accessing marketing deals and services like Twitter

How a “missed call” in India can control a farm’s water use

Using text messages or iPhone apps to manage physical devices isn’t all that uncommon — think Zipcar’s door unlocking app or Verizon’s new apps to remotely manage thermostats and lighting. But what about using a missed call to manage crucial resources?