Burger King locations in St. Louis, MO experienced 18.5 percent more foot traffic compared to other locations of the fast-food chain after the launch of the plant-based Impossible Whopper, according to statistics gathered by research firm inMarket inInsights. The firm analyzed location data from mobile apps to determine foot traffic at Burger King in March and compared it to that of overall foot traffic in April—when Burger King launched the plant-based option at 59 test locations in St. Louis. While new and existing customers visited Burger King’s St. Louis locations in April, foot traffic at all other outposts outside of the Impossible Whopper test city fell by 1.75 percent from March’s average number of visits. “The Impossible Whopper is performing very well in our test markets, and it continues to drive new traffic to our restaurants,” Burger King spokeswoman Dori Robau Alvarez said. Due to its overwhelming success, Burger King announced that it would expand the Impossible Whopper—ordered vegan by omitting mayonnaise—to its more than 7,200 locations nationwide, starting with Miami, FL, Montgomery, AL, and Columbus, GA. Last week, the Impossible Whopper made its European debut at Burger King locations across Sweden.