I left most electronic equipment on 24/7 and my average usage is about 650KWH a month, that is without AC. Twice during AC months. All my TV is LED. Gotta to love it. Every time I replace CFL with LED, the KWH did noticeable decreased. It appears that LED lights does make difference. There are much more left to replace, and I'm waiting for these specialty LED bulbs to go down before I can buy it.
Yes, I have three computer running 24/7, and it does not cost me much.
There was few summer months during first three years of Central AC operation, they were running 24/7. I called the HVAC company who installed my AC. They kept saying it is normal. I don't believe it was. My house was ok, I cant tell the difference because it was my first year owning house. For first three years, every spring, my AC went dead. Called them, and they refill freon. same issue then next spring same thing and third they found the leak, can't fix, so had to replace one unit. It wasn't working ok until I decided call another company, they found the source of problem and fixed. And told me the furnace was not set properly so fixed that. Finally never see triple KWH since then. Pissed me off yes, but what can I do? All I could do is never contact the first contractor and spread word about that contractor.

Now I can tell difference, my house is much much comfortable during summer time after that second contractor fixed the problem for the first time and never had problem other than burnt out capacitor. I let them replace it. I could replace capacitor myself, but the chance of it fry the compressor isn't worth it. Cheap insurance let them do it. My AC system is using the illegal freon as of three years ago. Meaning, if they are broken, and had to replace whole thing, then must use newer freon.
First year with wood stove, I use furnace fan, and did 24/7 man! the electricity bill increased by 40% So, I decided add another thermostat (Set cool always, just to kick the furnace fan but not AC) downstairs where woodstove is on the second year, and decided to move cold air return from first floor to basement (It looks pretty much like first floor instead of basement) where the woodstove is. MAN! after tweaking and let the furnace fan operation automatically when that woodstove room reach 90 degrees. The whole house toasty warm, and electric bill dropped back to as if furnace fan isn't being used.