Ok, this is sort of evil, but whatever...
I couldn't figure out why the other day when I was playing, I was getting loads of cash from fighting, but the last few times, I was just getting my tail kicked for a couple hundred bucks, and was spending more on the spa than banking. Then, I realized that the other day, I was playing before work at 5AM EST, which means most people have been logged off and their job building money NOT in the bank while they were sleeping. Again I'm playing at 5AM, and again, loads of cash.
PS - I'm one of the smallest houses in my Level, so I'm one of those that spends most people's normal waking hours constantly in the spa. So I don't care if I'm not fighting fair.