Bit late to the boat but:

Around $700/mo from a themeforest account.

And the more interesting story, about £4.5k/mo from a cleaning business that i bought.

I will at some point write the story up, but the TL:DR is: Spotted vastly under valued cleaning business with complete staff. Turnover of previous owner £190k a year. Profit of previous owner £18k. Yup, £18k.... Bought it for £13.5k.

Still in the early stages and still changing things but the previous owner was/is in massive debt, little free time to put into the business, did EVERYTHING on paper/fax/phone and had enormous monthly costs.

Theres a much longer story to this but i'll write it up in a few months when its a bit more proven.