Pros
I worked delivery for about half a year while I was teaching part time. The people at this company are pretty accommodating to their employee's schedule at other jobs. They just expect in return once in awhile you can pick up a shift if something happens with another driver.
The pay is commission based (per delivery plus tip) not hourly.
When I would cover an extra Friday they usually only ask for the busy hours 5-8 and if it wasn't too busy would cut you early. If you wanted to stay on they were fine with that as well.
During the busy eating hours there were usually plenty of deliveries available and the people coordinating where to go at the office are pretty good about keeping the driving to a minimum.
Cons
Sometimes you get to restaurants and the food is nowhere near ready then you are stuck just standing in people's way sometimes in a cramped place waiting on an order, most places have room for you to wait but the ones that didn't were always annoying.
Day to day the money you make fluctuates, but over a longer period of time you can expect a rather steady amount.