Where Do All The Broken Tees Come From?

Upon arriving at a par three, nearly every golfer I have ever observed has scrounged around for broken tees. There are always plenty available. In some cases, there are dozens scattered around the several tee sets.

This brings me to one of the enduring mysteries of publinks golf: If everyone is scrounging for broken tees, where are those tees coming from? Who are the people using new tees that provide the broken ones for everyone else?