If you want to track the location of a lot of "things" - say bicycles in a city, the trackers on the bikes need to phone home their location. If you were managing a fleet of 1000 bikes you probably couldn't afford a $25/month data plan for each tracking each bike. And you wouldn't be transmitting very much data per bike - just positional data. SO... what service providers would allow you to transmit a small amount of data per bike. What providers would allow you to send data using an aggregate data plan for numerous devices to that perhaps the per-device cost wound up more like $3/month??