Pros
You can set your own hours; easy going and friendly people you work with; don't have to talk to people or have passengers in your car. No one's going to puke in your car or assault you, a la Lyft or Uber. You don't have to park or find people's homes - you just wait on the curb and they come to you. You also get free food. It's easy to get a hold of the dispatch center if something is wrong.
Cons
The pay for a contract delivery driver through Spoonrocket is horrific. They're currently guaranteeing $18/hr, but this is before taxes and before your car expenses (which include gas and parking near their headquarters, which you must do 2-3 times per shift). They require you to plug their heated pack into your cigarette lighter, which took my MPG down to 13. Without the $18 guarantee, I was making about $12 per hour, before taxes and gas. It would be better if their dispatch center wasn't in the Tenderloin and you weren't required to either pay for street parking or idle illegally in the street.