Interesting idea if you aren't dealing with a heavy cloud cover like say Iowa or Illinois this might work. For taking pictures in a city this could be really useful.

But if you have to stay below the cloud cover you're going to probably cover no more than a township(?) at a time. If I have to send a guy out in a pickup who launches, grabs a photo, pulls it back in and then drives to the next township it is slow and expensive.

We are getting into aerial in the very near future.

People will be able to purchase very high resolution images from fixed wing and balloons.

(I am affiliated with SkyFi - CTO)