Why do people think an S1 will ever earn $15
after electricity costs?! Before you factor in the cost of electricity, it only earns $0.80 per day. And at 2w/GHs it will probably cost a $1.00 per day to run, lol.
Have fun and get rich! What could possibly go wrong?

It depends on how his house is heated. If he has electric heat, then his electricity costs are effectively zero. All the energy used to run the miner is subtracted from the energy needed to heat the house. He just has to turn it off when the weather gets warm!