Paul Graham wrote that a good early growth rate is something like 5–7% a week, and a great one is around 10%. Whatever your number, it's almost certainly the one you should be staring at.
Weekly growth is the right metric because it forces you to do something this week. Monthly numbers let you tell yourself a story. Weekly numbers don't.
The compounding is also unreal. You won't keep an early rate forever. But you can structure the company to find out exactly when it breaks, and why, the week it does.