That’s only sort of true, depending on how they do it. They advertise “promotional credits” which I assume do fall under the category of marketing expenses. Yesterday, I saw an ad that gave me a code for a $100 delivery credit from DoorDash. If I use it, my receipt will show a charge for delivery, and then a promotional credit that offsets that. I believe those credits can be reported as marketing expenses, and revenue would be the gross amount of the charge.