It wasn't exactly a business, but a couple of friends and I used to buy suburban railway tickets from the automatic vending machine. The machine required a smartcard whose minimum denomination was 10x the maximum ticket price, so people would rather wait in long ques to get the ticket from the clerk rather than use the ATVM. We bought some cards and people were happy to buy tickets through us for a small surcharge. We also made money on recharge options for the smart card. There were others who did the same thing and this is where I got my first taste at stealing customers.

As for the outcome, we got bored after we had saved enough for a PS3 ;)