You're a frog in a well. Do your own sum. Car rental is 90-120 a day. Diesel 50. Each fare is 10-20 dollars. 300 revenue a day isn't that hard.

The smart ones wait in strategic areas. There are different strategic areas at different time of the day. The smarter ones do extra business by sending kids to/from school every day, and charge just slightly more than the school bus.

The super smart ones can even do forex / stock trading while on the move, better than those lazy bums who only sit at home and lose money in the game of pseudo science.