The system was created by agency Clemenger BBDO Melbourne as a development on its "You're Not You When You're Hungry" campaign.
It's built on a 3000-word algorithm that analyses around 14,000 social media posts per day.
When trawling these posts, the Hungerithm registers whether or not people are happy or angry. The angrier these social media users are, the cheaper the Snickers bar becomes in price to appease them.
Customers can also lock in a price for a Snickers bar with their smartphone - see the video below for more details.
The system has been rolled out to Australian 7-Eleven stores first, but the brand said it will be introduced globally in 2017.
A Snickers bar usually costs AU$1.09 in the land down under, but an unhappy social media crowd dropped the price to about 59 Australian cents on Tuesday.
The Snickers bar price can be updated more than 140 times a day and dip as low as 82 percent off.
"Considering how quickly the Internet can swing from a place of sharing and enlightenment to one of incredible vitriol, we felt this was the perfect way to bring the, 'You're Not You When You're Hungry' platform to life," Clemenger BBDO Melbourne executive creative director Ant Keogh told Adweek.
"A data-led idea that changes the price of a global FMCG brand is an amazing opportunity. To launch it at scale through 7-Eleven is something else again."