Rarity, nicknamed "fancy pony", decided to go to the three princesses. She asked if she could sell them bracelets for the royal guards so that they would feel special. Considering the dropping rate of guards they had, they immediately agreed.
They all got customized bracelets, and the rate of guards for the castle increased by one million percent. Then, one day Rarity got a sack full of one million gold coins. Then, she built an empire of bracelets, and was in charge of the Royal guard. She also got her nickname upgraded to "fancy bracelet pony".
Then, with her friend Fluttershy ( who goes by the nickname of "butterfly", she started selling necklaces as well, and became the richest non-royalty in the history of Equestria.