The Bitcoin days destroyed question has a pretty good answer explaining the concept and it was posted on hackernews. That's why it is so popular

12 months payout is great if it actually happens. Depending on your electricity price you may never break even. Even if prices remain the same, difficulty will probably rise until the average production cost on an FPGA matches market price.

Interesting discussion here (since every thread in this board has random content, I hadn't actually noticed this). I have been thinking about how to predict difficulty, mainly because I might buy an FPGA and also because I want to add fancy charts to my calculator , but it is almost as hard to predict as Bitcoin price.

I agree with most of what has been written. I think that the average Mhash/J plays a very important factor here and, as soon as FPGAs come out, difficulty will rise a lot, regardless of the price. Every time new mining hardware comes out, difficulty will increase and electricity price will always be the bottleneck. So even if you buy a fancy new FPGA to save on electricity costs, the higher difficulty will make mining barely profitable again. Unless of course, we see price swings like we saw in June, but I highly doubt that.

Good ideia. 

There was a recent question at Bitcoin SE that might be relevant: How can I accept Bitcoin donations on my blog or site?

If you have problems use another exchange. There are plenty.

Maybe, but not right now. I still have a few issues to iron out...

Possibly. Depends on the factors mentioned above (see the link I posted). The fees you are talking about are charged by exchanges when you convert bitcoins to dollars and vice versa. These fees are used by the network to avoid spam transactions.

A miner tries to find blocks. When he finds one, he earns 50 bitcoins + money from the transaction fees he included in the block. The problem is that it is really hard to find blocks right now unless you have a cluster of GPUs. So if you set up a miner to include your transactions, you will have to wait until your miner finds a block and that could take a really long time (i.e. months).

You don't really have to pay fees. If you use an ewallet (CampBX, MtGox, TradeHill, etc.) you can always send bitcoins for free. If you want to use the client, there is a patch somewhere to avoid fees. The problem is that a transaction that doesn't pay fees can take a lot of time to process depending on a number of factors. See the fee structure here: http://bitcoin.stackexchange.com/a/190/5

So if you have 10 Bitcoins that are one week old and came from one address, you can send those bitcoins in small amounts without paying anything.

Try CampBX then? 

MtGox is the best due to its high volume and market depth. Other exchanges don't even come near that. However, everytime I need bitcoins I specifically don't buy them at MtGox, even if I have to pay a few cents extra somewhere else. I have nothing against them, but "80% volume as of July 2011" is not my idea of a decentralized currency.

That's their job. Anyway, how is it possible to withdraw that many coins? Isn't there a daily limit?

If you want bitcoins you should buy them. Mining is not profitable at the moment for most people...

Probably with none. Your CPU shouldn't get you much more than that. Check that wiki link to find out.

You pay fees if you use recently acquired coins and/or if you are sending coins that you received from several different addresses (ie if you have a large number of "inputs" to collect from). How recent are the coins you are trying to send?

I think they are talking about a service that allows you to charge your account with bitcoins and then use  it to make payments in Eur/USD. I don't know if there is something like that... Maybe OKPay?

$2 - $3 is more unstable than $12 - $15. A drop from $3 to $2 means that I lost 1/3 my money while a drop from $15 to $12 means that I lost 1/5.

While it is true that difficulty follows price, it is also true that miners are a big part of the selling force at the markets. That selling force will halve in 2013, so this could create some upward pressure in the markets. But then again, there are so many things that affect price... We've seen a 90% drop and the bitcoins per block are still at 50.

I don't have MS Office right now, but I will check it later on Windows. I took a peek using google docs and there are a lot of things there. Are you talking about ROI (cost to generate/sell price)?


I also agree, but I think that in the following months we will see a shift towards FPGAs. If a relatively cheap (say 1$/Mhash or so) FPGA becomes available, the network will adjust and mining with a GPU will not be profitable for most people. Of course there will be a transition period (not sure how long, though...).

Espero que eles sejam presos. Já está mais que na hora...