What you mean how to scale it?
If you found a profitable campaign that works for you it means that
1- You have paid to showcase your ads on facebook
2- you have seen that it produces money
Now, if with those 2 steps you are not sure of how to scale, it sounds to me as if you should head back to kindergarten.
Seriously man, I think the maths are pretty straight forward no?
You pay ----- Display ads ----- Users click ---- You get money
I believe you would have to pay so you can display more ads and more users click on your ads so you get more money.