rizwanali - You are exactly right.
But now a days many even don't like mining bitcoin who can have the best calculations, my buddy do recommended me.
have a look on coinware to understand what is happening, you can analyse the profits, usage etc.
Free electricity is better 
how ever solar/ wind energy is even a better way to opt.
You know in canada it is 0.35 kw/h, it is higher than most parts of europe, and the regular price is 0.06$ in QC - Canada.
Look on the Metrics at central washing ton it is 0.027 kw/h.
it is like we need to spend $10 to earn $4 sometimes.