best way to earn money quickly

I already own squeaky voiced teen and lemon tree. In fact i think lemon tree was the first or second mb i opened after the tutorial, I also got 10 white picket fences pretty early too. Do they have any multipliers?


All in all i now have 14.95% increased money and xp +5% conformity bonus... In other words not so much yet. Hopefully i can get to tennis courts quickly