When i was 13 i used to work a Saturday job in a chippy carting the sacks of tatties from the shed at the end of a yard to the peeler machine, and then pour them into the chipper. I made £20 a weekend, which was like a bar of gold to me in them days.
Then when i was at Uni, i worked Thursday, Friday and Saturday night in a Pizza shop delivering. I got £5 per hour, plus £1 per delivery. You can take 6 - 9 pizzas out at a time depending on distance, and do a round in 30 Min's or less if you fly.
From 7pm till 2am, you could earn on a busy night (which was most nights) You could earn a good hundred pounds per night plus tips. Every door i went to, i never had any change (Because it was in the glove box

), the only solution if they don't have any either, was i take the money and come back with some change from the garage. They never wanted to wait and most would say "Ah don't worry about it, keep the couple of quid", it soon adds up at 15 deliveries an hour, especially after 11pm when they just got home from the pub half cut and wanting food.
Even the vehicle was provided by the shop, so i didnt even have fuel etc to pay for
The guy who owned it, drove around in a brand new BMW, and had a lovely home.
People are thick, if you serve them perfect food for 10 yrs they will come back every time. You mess them around once, they will try somewhere else forgetting about the 9.5 yrs before and probably never come back to you again.
Once people like somewhere, they will keep going back and even recommend you, as they know it will be good, and would rather buy from you, even paying you a little extra, than risk a new place not knowing what they will get.
Your sitting on a gold mine if you can put up with the dirt, smell (which gets into everything) and nutters on a Friday and Saturday night.
Ive often thought about jacking all this in and doing something completely different, and one of the things i would consider, is a fast food shop. But i have always wanted to do a fast health food shop with delivery. Stuff like good main course meals, baked tatties, salads, fish (not in batter) Italian (not pizzas lol), not rubbish or pre-frozen junk.
Traditional Businesses are always the best, tried and tested.