Quote:
I've found that the higher your earnings per day, the better the reward. You might want to try switching them on while doing the challenge and back off after.
I don't think this is true. I had 400m/h (20 energy) and was getting 700m per win when challenges started. Later I lowered income to 60m/h (4 energy) and currently when I win a challenge I get 800M. Maybe it depends on some girl stats (I keep upgrading them) or something else, but not on income on cash panel. I have only 1 girl that can win around rank 17 from time to time, so I can't test winning with another girl.