when did the elf on a shelf start

The Elf on the Shelf tradition began in 2005 when two sisters, Chanda and Christa Bell, came up with the idea of creating an elf figure that could watch children's behavior during the holiday season. The sisters believed that if children thought the elf was watching them, they would behave better in anticipation of receiving gifts from Santa Claus. The idea caught on quickly, and the Elf on the Shelf has been a beloved Christmas tradition ever since.