When you think of it, Santa Claus is a rather unlikely figure. Living at the North Pole, flying around on Christmas Eve, going down chimneys to deliver presents to good little girls and boys.
Everybody knows that the presents are actually from Mom and Dad. Everybody keeps up the pretense, and when the "deception" gets revealed, it can be a bit traumatic for the kids.
Why does this myth persist? Why do kids believe in Santa Claus in the face of vast evidence? Why do parents keep it up? It seems odd that marketing alone could explain what's going on.
A Trip to Arizona
The Pueblo Indians of the Southwest have a colorful religion called the Kachina Cult. The best known of the pueblo tribes following the kachina cult are the Hopi, of northern Arizona. Good information on the kachina cults is hard to come by; most info I've found on the Web seems to be either from art galleries selling "kachina dolls" or first year anthropology students with no real clues. Beware -- studies of "primitive" religions almost always slide into the quagmire of "mine's better than yours" or "lookit the funny people".
Anyway, everything, in this religion, has a spirit, called a kachina. They're not Gods to be worshipped, but rather spirits that may be helpful if treated right. You can't communicate directly with a kachina; you have to communicate with something else that has somehow gotten a part of the kachina's spirit. One way to do this is through dance. Dancers put on masks representing particular kachinas. The dances represent interactions between spirits and humans and hopefully will influence the real kachinas to to what the dancers want.
All very photogenic. The dances are complex, the costumes are spectacular, and everybody gets a lot of nice pictures. At least in the public version ....
Think of what this looks like to children. Their village is being visited by these spirits, who will determine how well everything in the village does for the next year. The spirits are great and mysterious, with awesome powers. Not like anybody we know, surely.
Now think of a boy being introduced to the cult (it's men-only). For the first time, he is allowed "backstage", and sees that all of the "spirits" are "really" the men that he sees every day. Now, he is expected to help maintain the illusion for the women and children.
Santa Claus is the Kachina of Christmas
Everybody does it for the kids. When a kid gets old enough to stop believing, he or she is old enough to help in maintaining the illusion for the younger kids. As to why the illusion doesn't really bother anybody (and kids aren't bothered by a zillion different shopping mall and advertising Santas), well, it's a kachina dancer. None of the Santas that you see is the "real" Santa, but each has (hopefully!) some small fragment of the spirit of the "real" Santa. And it will only be there if everybody works at maintaining the illusion.
The Hopi are definitely onto something here.
Note -- This isn't my idea. I don't remember where I first saw it, and I can't find anything on the Web. Anyway, for whoever came up with it, thanks for a really good idea.