Managed by 20-something bar floozies which is 1/2 their problem (I saw a Twitter post of one). You'll wind up shopping/delivering not necessarily groceries but bulk cargo in your own vehicle for $5 and a tip if you get lucky.
The average customer in Chicago orders multiple 24 roll packs of toilet paper, beer for the year and 5 cases of Ice Mountain water to be delivered to a 35th floor with no parking area (bring lotsa quarters and budget for tickets and maybe even towing). I had to cancel a delivery order from Costco because I wasn't about to break the struts in my newer passenger vehicle (you get like $7 for Costco orders). Promised tips would be split between the actual shopper and driver for the Costco orders and never saw a nickel. The service is abused and the workers are exploited.