Jamie Siminoff, the founder of DoorBot was initially rejected on Shark Tank in 2013.

Jamie Siminoff, the founder of DoorBot (which later became Ring), was initially rejected on Shark Tank in 2013.

Despite not securing a deal, Siminoff persisted, and Ring grew into a major player in the smart home security industry.

In 2018, Amazon acquired Ring for over $1 billion, making Siminoff a billionaire. In a full-circle moment, Siminoff later returned to Shark Tank as a guest investor, taking a seat alongside the very sharks who had once passed on his idea.