Santa Claus' image has found its way onto soda cans, billboards and commercials as a way to sell products.  Retailers have a stake in convincing us he's real, but we have no concrete evidence to that fact. 

Not every "nice" person gets what they want for Christmas, while "naughty" people often get piles of presents.  The "Clausian" work ethic, if it existed, would prevent this sort of injustice.  Furthermore, there are over one billion people theoretically eligible for gifts on Christmas.  It would take a huge factory of elves in the North Pole to meet that demand, and even satellite photography has failed to find evidence such a place exists.