My Starbucks app is still linked to my credit card. So they must still pay the interchange fee... Also why would Starbucks form an alliance with McDonald's? Th

My Starbucks app is still linked to my credit card. So they must still pay the interchange fee... Also why would Starbucks form an alliance with McDonald's? They compete in the same market. They both sell coffee and breakfast sandwiches... Would be a bad idea for sbux.