nowhere on the site is written how exactly is profitability calculated. I just don't believe that GPUs worth 10BTC would be 60 times (= 6000%) profitable (mining LTC) than ASICs worth 10BTC (mining BTC).
Well, I've been GPU mining and comparing results of mining BTC vs altcoins. These estimates on the site are accurate.
Try it yourself if you don't believe it. Mine with a GPU (or even a CPU) for 24h BTC, then 24h altcoins, convert to BTC and compare.
The numbers behind are here. Check the thread.
The other problem is the change in difficulty could be different. We can't make decisions based only upon NOW, we need to make decisions based upon projections into the next 2-3 months. 6000% more than zero doesn't make sense. Right now, GPU mining bitcoins makes you some money, but less than the power costs. 6000% more profit might cover power, but it might not, you need to do that calculation. Then you need to include the rate of change of LTC difficulty. To me, 100$ per card + power supply, mobo, etc, call it $500 charitably (probably would actually cost way more), making 5$ per day will take 100 days to break even, except if the difficulty increases just 5% every 14 days, it will take *way* longer because by the end of 100 days you are making only 60% as much per day. And I just made up 5%, it's probably higher with all the people switching away from bitcoin mining...
The best evidence to consider would be a table with rows like this:
Cost of miner, daily/weekly return at the time we would receive it, estimated rate of difficulty change
Then the math is pretty straightforward to calculate the time-to-break-even and profit-per-unit-investment.
