Basically, all the 5vdc is used for, is to provide power for the signal for the Gecko drives to work. Which is according to Mariss, is only 16mA.
You should still connect ground (or 0V) to the common. Mariss comment about the 5v line being the return, is because current actually flows from the lower voltage to the higher one. (Think of a battery with + & - terminals. The battery looses current from the - terminal and gets it back at the + terminal). This doesn't normally concern the average person, but for the people designing circuits (ie mariss) it is a basic fact.
Moray |