(From the archives, written in 2013)
CUTTING A KEY
When someone pays money to someone else they expect to get what they pay for. When someone does something for someone else they expect something back, usually money.
No one pays for nothing and no one does anything without getting paid or at least receiving something of value equal to what it is they do.
For example I want a a key to my front door cut. There is a nice little ironmongers down the road that always does a great job of cutting keys so I decide to go there. I take a five pound note with me because I’m not sure exactly how much it will cost me to get the key cut.