When I was a teenager I saw a magic lecture (Michael Close?) where they did a trick that left the audience with a little prop. I think it was an origami bunny from a dollar bill. The lecturer said that clients could see that the magician was actually working by how many people had the origami bunny.
The idea of having something visual that people walked around with after you performed for them has stuck with me. I’ve had versions of things over the years. Currently the end of my ambitious card has the face of the card peeled off and stuck to the person who drew on the card’s shirt.
Recently I was performing at a large event and afterwards the booker commented on how many people had my cards on their shirts. Having visual reminders for bookers that you’re there and working is smart! While not 100% necessary, it is helpful at large events where the booker may never see you.