Pretty well-written article. I'd change the last sentence of your first paragraph to not reference any specific number of coins received, because that number changes (as you point out later).
The first one to solve the problem receives bitcoins for his work.
ROI, while very much discussed, really has nothing to do with mining. Sure, we'd all like to make a good return on our investment, but the fact is that our profit or loss is not a part of the mining process.
Your definition of Hash is confusing. The hash is not the number of calculations a miner runs through in a second. That would be h/s, or kh/s, or th/s, etc, and you do a fine job of explaining those. Your second sentence is a better explanation of what a hash is. I'd just write that as
A hash is a possible solution for a block.
Your definition of ASIC states, "In general, an ASIC is an electronic chip designed for a specific use." It's not "in general" at all, it's exactly what it is. Ditch the "in general" lead in of that sentence.
When you're defining a block, you state, "see above" for the definition of the block chain, when in reality, you explain block chain below
.
A bit later you state this:
As explained above, a block contains all of the Bitcoin transactions sent during the time before the block is found.
That's not true. A block may contain all of those transactions, some of those transactions, or it may contain none of them at all.
I'm being a bit picky here, but you state that the blocks prevent double spending and attacks on the network. Well... the transactions included in blocks that are on the accepted block chain prevent the double spends because they show the sender no longer has ownership of the coins. I'm also not really sure how a block prevents an attack on the network. I'm more inclined to accept that the sheer size of the network and the difficulty in controlling over 50% of it is what prevents an attack. Maybe you're thinking about some other kind of attack here?
When explaining mining specifics you mention the fee of 0.0001
BTC. You might want to include that the fee is for every kb of data in your transaction. For example, somebody sending 1
BTC as a single input would only have to include that 0.0001
BTC; however, somebody sending that same 1
BTC with 1000 inputs would likely have to pay a higher fee.
A miner is not necessarily generating millions of hashes a second. Just state that the miner is generating hashes per second... or since earlier you stated the most common measure of hashing power is GH/s, you could state that a typical hardware miner is generating billions of hashes per second.
Please don't tell people to try and find ways to take advantage of things like utilities included in rent. Sure, if you plug a smaller miner like a U3 into the wall and run it, it might not make much of a difference at 63 watts of consumption. However, you start plugging in multiple miners drawing kW of power, that's akin to stealing. Somebody's going to notice your electricity usage is way above what is considered normal and fair. There's no such thing as free electricity. Somebody's paying for it.
The mining calculators typically either don't account for changes in difficulty, or only allow you to enter a static value (like 5% increase). You do a good job explaining that just because a calculator says you're going to earn X, you're probably not going to make X.
I like the little walk through time you've got at the end
