The Pop Dongle is a device that plugs into the audio jack of an iPhone or iPod and emits the scent of popcorn when a user swipes a butter icon while playing the game Poptopia. It was created by Pop Secret and Deutsch to enhance the gaming experience and increase interest in the game. Users find it easy to use and it has a nominal price. Studies show it leads to positive feelings and higher engagement, demonstrating it is a customer-induced innovation that has gained sales. Experts recommend ad agencies develop novel technologies like this to promote brands.