A: What percentage of pictures taken with a cameraphone are erased
without ever being copied from the device? B: What percentage are
removed from the device via USB, Wifi, Bluetooth, or other
non-billable methods? (This would leave "C", the percentage of
pictures taken that are sent from the phone over the carrier's
network. A+B+C = 100%)

Well on my camera phone most pictures are just deleted. A few I keep
on the phone for backgrounds etc. or just to show to someone (take a
picture to show my wife later then delete it). A very few I upload to
my carriers picture system because I want to share them with other
people. Unfortunately here in Canada none of the carriers allow you to
download your pictures with a data cable. I am sure there will be a
hack eventually, but at the moment it isn't possible.

If I had a cable I would save a lot more pictures than I do. I'd
probably take a lot more pictures too.