What happens though is that the goal posts move, and of course if you get yours late and the difficulty has increased after you get one and you're under performing, well you lose. A number of people on the various forums claim to have made money on their miner setups as well but the forums are not really verifiable sources.
As far as I can tell it works when the market price for bitcoin greatly exceeds their cost to produce, and that seems to happen frequently.
Think of it absolutist terms, denominated only in BTC. If you buy a bitcoin miner, today, for 50btc, what do you think your odds are for mining 50btc + enough extra to pay for electricity before the device either fails or is obsolete, or returns at such a low rate you might as well of stuck your money in municipal bonds?
Seems like a kind of useless way to look at it though since the goal here seems to be dollars, not btc. So what insight do you gain by evaluating it this way?
