Okay it is profitable if you have a decent pc already built and your power is under 13 cents a kwatt.
If you don't have any gear at all that is a different story.
So
a ) what part of the world do you live in? I ask because the price of gear and power varies place to place.
b) what is your power cost please use usa cents per kwatt
c) what kind of a pc do you own?
d) if you don't have any good gear do you need a pc for other things.
here is a store built pc that would make money if you owned it already and if you went to buy it it would not make a profit for a long time.
http://store.hp.com/us/en/PDPStdView?catalogId=10051&urlLangId=-1&langId=-1&productId=1501157&storeId=10151