I don't have one.
I admit that I'm a bit of a hound dog when it comes to tracking. I like to make sure that my customers are receiving their parcels as quickly as they're promised. I will keep on top of my tracking and my delivery schedules with my iPhone and the Canada Post app in case something goes off the rails, as did happen recently with something I had sold to a buyer in Calgary. She'd come back twice within a week to buy more of the same, so I knew she was a satisfied customer, and I wanted to make sure she was getting her orders as quickly as they were promised. One item that was shipped in a smaller box just disappeared after I dropped it off at the post office.