Bob, I've got a wonderful machine to sell you
It's a generator and electric motor in one. After you have wound it up by hand, it keeps delivering energy FOREVER.
no more power bills.
of course, if you don't use the right lubricant, the friction will build up and the motor will stall.
BUT WAIT!
I can sell you a genuine micro-encapsulated lubricant system that will guarantee perfect performance.
And it will generate limitless quantities of fresh clean drinking water, even on Mars...