It seems like to me that the cartridges are designed to give you about 10 good hits. Then after that, you really do need to drip, in my very humble opinion. I also notice that when I buy the high-end carts plus use e-liquid, I don't need to change carts that often. Very good material in the high-end carts.
10 good hits? maybe super mini carts, I've never tried them.. but my pen carts last me a good 10 cigs worth, sometimes more. 10 hits is less than 1 cigs worth to me