Upload & Sell: Off
I was reading online that there was a maximum length to the cable, but it might just be random online hysteria floating around.
There's a technical limit of 5 meters or 16 feet for USB 2.0. The reason for this is that 5m of cable allows for the maximum time limit for a signal to be sent to a device and receive a reply before a timeout between the devices. Any longer and the original device will consider the signal lost.
One solution is to use a USB hub/repeater, but even then you're still limited to a few hops.
Tethered shooting is nice but there are some other solutions as well, including Eye-Fi cards for some cameras, and Canon's own wireless transmitters. Capture One has a really nice piece of software for displaying photos taken through wired tethering and then accessed on something like an Ipad: Capture Pilot.
Lots of solutions