Our plant runs 24/4 and our electric bill is huge. We run during peak, off peak, and are always pulling a ton of KW/h. Our electric bill is $15,000+ per month in NC.
Guess what? Even when you factor in peak, and off peak hours, our average charge comes out to 12 cents per KW. Tesla charges 28 cents in NC to use supercharging network. So, let's just say for simplicity sakes they are doubling their money.
I don't know about you, but covering your "costs" can mean a WHOLE bunch of things. Cost can include administrative overhead, direct operating expenses, maintenance, insurance, etc. and they could be adding in payback for the SC stalls themselves. Tesla is clearly charging an inflated price now to cover the gross mismanagement of free supercharging and high overhead.
What I'm saying, is charge ONLY for the electricity that Tesla gets billed for plus the lot lease fee. That would add, depending on volume, only about 5 cents to the cost or roughly 17 cents per KW and that cost would decrease significantly with more traffic.
Tesla, since they don't advertise, should allocate what would be an Advertisement and sales budget to the SC network build out. A Supercharger is relatively cheap to build and with Tesla saving BILLIONS of dollars every year, they could add thousands every year with that money.