I encouraged my bipeds to trade from a very early age. This began as treats for sitting and for walking on the lead. Any chance to get more treats is a good thing!
As a puppy, I usually only had one or two toys available to me at a time. They would swap them most days, so that the toy was always interesting and I didn’t get bored with it. I also always had a nice chew available, so that I had no need to chew the furniture. That was their theory – I still felt that I’d like to test various items of furniture for chewing, but that’s another story.