Have the stores release apps (or one app that works for the system they use) that trades a percentage off, coupons, etc, for location data. "We'd like to learn

Have the stores release apps (or one app that works for the system they use) that trades a percentage off, coupons, etc, for location data. "We'd like to learn a little about your shopping habits, and that includes sending anonymized data about your time in our store. In exchange for this, we'd love to offer you 25% off this purchase and 10% off all future purchases".