The quicker a consumer can get to a Meat Pack store, the bigger the discount.

Sneaky is the word for a mobile marketing campaign run by shoe store Meat Pack, located in Guatemala City, Guatemala. Meat Pack dubbed the campaign “Hijack” and that’s just what it did—steal consumers from competitors while they were in the competitors’ stores in the same mall.

The campaign targeted consumers who have downloaded the Meat Pack mobile app and who have approved the app to use their location via their smartphone’s GPS technology. Meat Pack mapped the mall, setting the precise GPS coordinates for the stores of competitors like Adidas, Converse, Nike, Puma and Reebok, according to a promotional video from Meat Pack. When a consumer with the Meat Pack app on their smartphone walked into a competing store, the Meat Pack app displayed a push notification message.

Opening the message, the consumer discovers they can get a discount on a Meat Pack purchase. But here’s the deal: The discount starts at 99% off and decreases one percentage point for every second it takes the consumer to get from the store they’re in to the Meat Pack store. The clock is ticking.

Meat Pack says it hijacked 600 customers in a week, with one quick-sprinting shopper earning an 89% discount, the promotional video notes. The app stopped the clock when a customer arrived at the GPS coordinates of the Meat Pack store. And when the clock stopped, the app automatically sent a post to that app user’s Facebook page showing the discount they earned if the app user had entered their Facebook credentials in the app.

“What a great campaign,” says Nikki Baird, a managing partner at Retail Systems Research LLC. “I’m not sure how long-lived it can really be—campaigns like this strike me as prone to Cold War-like escalations that lead to mutually assured destruction among competitive retailers, so as a long-term strategy I hesitate to say that it has a lot of potential. But as a way to make customers aware that the brand has an active mobile presence, I think it’s great.”