Haddon Sundblom
Santa 1931

"A young man dives into the tub like a real rascal, but upon contact with the liquid exclaims: Vaffancuore. This is the terrible dark non-alcoholic drink. Help, Superyoung!" (Elio e le Storie Tese)

In short, the story is very simple: in 1930 the Coca-Cola company was looking for a powerful spokesperson for their Christmas campaigns: the D'Arcy agency presented a work by one of their illustrators (Sundblom) that was so well-received that this Santa Claus became Santa Claus (up to today) and not just in the ads of the famous beverage. In reality, that Santa Claus did not come tout court from the creativity of Sundblom: aside from the colors (go Lane go) which were "mandatory", the illustrator was inspired by images from Scandinavian iconography (though "de-elfing" them), a poem by Clement Clark Moore ("A Visit from Saint Nicholas", 1822), and a neighbor of his (for the features), until the neighbor's death (then he used himself and his family members: the inspiration for his last work for the Coca-Cola Company is unknown).

So far the chronicle. Speaking of "mythology" it would be too simplistic to insist on the urban legend that the Atlanta holding "invented" Santa Claus, at most it can be said that they "beverized" the iconography. I have no information that the Georgians have ever "reacted" to all the Santas (not theirs) seen around (they could easily represent the greatest intellectual property theft in the history of humanity): if you have any information/explanation please share it.

In short, the primary question isn't whether the children of the western world without Coca-Cola would have been deprived of the joy of a supernatural gift (anyway "they would have thought of it" with Santa Lucia or the Befana) but what triggered the popular imagination to "canonize" an advertising image and "iconize" its "sacred attributes". There is no answer or maybe, who knows, it might be gone with the wind (avoiding boring you with tedious Pop theses: during the holidays we're all a bit nicer) but certainly, at its core, there's the same mechanism (in different chronological and cultural contexts) as the theft of Mithra's birthday.

Watch out for the coal.