Ever see one of those tacky corporate-sponsored Snapchat filters with snowflakes falling over red Starbucks cups and wonder, “Does this really work on anyone?

Well, if you’re an advertiser, now you’ll know.

The Ghost unveiled a feature (creatively named “Snap to Store”), that uses Foursquare location data to tie filter users to their in-store visits.

And results seem… profitable

In the beta test, Snapchat reported 42k people visiting Wendy’s the same week they sponsored a spicy fresco chicken sandwich filter. Muy picante.

And it kind of makes sense. Over 66% of Snapchat’s 158m users open the app while at the mall, and 80% while at a restaurant — both prime inception times for advertisers.

But because Snapchat doesn’t collect background data, it can only track users who opened the app while at, say, Wendy’s.

This is them playing ketchup

Snapchat has resisted hyper-targeting users but, with a struggling stock price, the move is an attempt to keep up with Facebook and Groupon, which have been doing this for years.

Moral of the story? When your competition is stealing users by blatantly copying your product, sometimes it’s ok to copy back.