The thing I don't get: Customer orders a hamburger and DoorDash charges, say $15. The restaurant charges $12. DoorDash guarantees $9.87 or whatever to the driver. Generally a customer is not going to tip more than $4-5 for a $15 order. So how is this sustainable? But DoorDash obviously chose their model to avoid sticker shock of $12 charges on a $12 meal.