@Epicfailz 

You do not need all three, you can give one node to your friend if you want, and you guys will have your own networks. Only thing I can think of that may be an issue is the serial numbers. All three should be tied together, just different letters like A, B, and C. So if you ever need to replacement, you will need to send all of the units. The manufacturer warranty is two years from the date of purchase so just wanted to point that out. Now if you looked at all the serial number and they are all completely different, then it would be no worry.