Two carts per day seems about right to me for a penstyle.
I'm usually a 10 cigarette per day smoker, and despite the claims of whoever is selling the carts, I really go through them fast (using "high" carts).
I think it's probably a combination of lower nicotine per puff and the fact that it's just so much easier to smoke e-cigs than regular cigarettes. I find myself puffing much more often.
I'm hoping e-liquid is the solution. The carts (even when I'm not paying Njoy prices) are just too expensive.
My next step is finding a good supplier of e-liquid