I'm going to share ALL the data and statistics drawn from 47 documented nights delivering food for DoorDash Incorporated. The 'gig economy' is a vast and unpredictable beast, but this particular corner of it actually works well as a part time job to make some money on the side.
First, let me set the stage. Usually doing 6 nights a week several weeks in a row, I've managed to make in excess of $2,600 over 47 nights , usually between the hours of 5 - 9 PM. I live in a large and relatively wealthy suburb of Atlanta, Georgia, USA in an area with a booming restaurant scene and where the DoorDash app is quite popular. It's a great area for such a side gig as there are many upper middle class residents around who may be inclined to tip more and there are lots of popular restaurants in a central location.

Over the course of a night, usually working somewhere between 3 and 4 hours, I naturally might get drawn out towards other areas, but I have a location I always drive back to as it is a hotspot for restaurants. The app displays the locations of restaurants that have been receiving lots of orders, but I usually just hole up in the alley behind Taqueria Tsunami because it's so close to so many other restaurants.
Now, for the data. I compiled a spreadsheet containing all data points I collected and several important and interesting statistics. I only worked one day where I forgot to record my data, so this list is pretty comprehensive.

I'll pick out the most interesting and relevant statistics here. In total, I managed to earn $2,627.98 over the course of 47 days working a grand total of 160.7 hours. That gives me an average earning of $56 per night with a projected $16 per hour.
However, one of the defining characteristics of the gig economy is how uncertain your income can be. Take May 25th for example. I made $34 over 3.5 hours. 3.5 hours is also my median hours worked but puts that night at almost half my median earnings of $60.

On the vertical axis, we have my earnings per night. On the horizontal axis, we have, respectively, hours worked and miles driven. As you can see, earnings trend up with more hours worked for obvious reasons. However, the average variance between values is huge and only gets larger the longer I work. It's an unpredictable business.
And on the graph of miles driven, you can see the values sort of plateau. Sometimes you just have to drive a lot further for your orders. I still maintained an average in excess of my goal of $1 a mile at $1.20. I generally don't accept orders with less than a dollar earned per mile, but that doesn't count return trips.
Speaking of wear and tear on your vehicle, I drove 2,215 miles in total while operating the Dasher app. The median miles driven per day was 45, a not insignificant amount. My own car, a sensible thoroughly depreciated domestic sedan, doesn't have high running costs, but gas isn't the expensive part of doing DoorDash. On the median night I mentioned, I might burn 1/8 of a tank to the tune of around $5. It's really the insurance that takes a bite, especially as a younger male driver, even with a totally clean driving record.
Depreciation also takes a bite too. My car isn't losing much value with each added mile, but doing Doordash with a newer leased vehicle might prove problematic with mileage limitations and the greater depreciation miles tend to add on newer cars. Keep in mind not all cars are as well suited to doing deliveries. Ideally, you want a car cheap to run with low insurance costs that is also small enough to squeeze into tight spots but pleasant enough to drive that you don't despise getting in and out for several hours. I think my humble Chevy Cruze fits the bill.
I have come to the conclusion that what DoorDash is good for is not making pocket money, but rather covering the expenses of car ownership you're probably already incurring, freeing up a greater portion of your regular income with just a little bit of gravy on top. My median hours worked of 3.5 is doable for a typical 9-5 job, but even with less free time you can make a good dent in that insurance bill at an average of $16 an hour working the peak dinner rush exclusively.
So, what do you think? Do I have enough data? Did I miss some obvious correlations? What do you want to know about the glamorous life of a Dasher?