When I was at university, there were a group of students running a service called Ring Bring. Basically, they were a delivery service for anything you wanted - you could send them to a takeaway for food, or to an off license for beer, or even (no doubt!) a supermarket for brownies.
I never used them though... I can't remember why, but I suspect they'd have to be rather expensive to make it a viable business... Even for students.
How much are you prepared to pay for your brownies?