Originally Posted by
elgreco
Oh yea. (This upcoming example isn't absolutely correct, but its the simplest way I can put it without writing a novel) There are 3600 brand new bitcoins minted every day. That number is constant, it doesn't change. When you are mining, you are fighting for your share of those coins. Your share of those coins is directly proportional to the amount of work you put in. If there are 100 units of work being performed for the network, and you are doing 10 of them, then you will get 3600*0.1=360BTC a day. In the beginning, there weren't that many units of work being performed, so your laptop was contributing a significant amount. Today, there is a ridiculous amount of work being performed, so even though your laptop can still do the work, its such a tiny amount that it wouldn't be profitable.
At 2 MH/s, you should earn 0.00000142 BTC/day on average (0.00000006 BTC/hr)
^^^ That's what your lappy would probably do now.
If what I wrote above communicated effectively, then you should now understand that the answer is "never".