Does anyone have an idea of the ROI on this? I'm thinking you'd need a massive number of 10 second to mine any meaningful number of BTC on consumer laptops.
10 minutes of mining = 30 * 10 * 60 = 18,000 hashes
Since Coinhive pays out 0.000090 XMR per million hashes (current rate as of Dec 11. 2017), that's $0.0004250394 per user (18000/1000000 * 0.000090 * 262.37).
In order to make $1, you would need 2,353 visitors with laptops mining for 10 minutes each.
I spent about $20 / year on lotto tickets (basically whenever Powerball gets near a record jackpot). That same amount of money will keep my i5 ThinkPad running for a long time. Am I more likely to mine some Bitcoin or win the lottery?
You're competing with computers that are made exclusively for bitcoin and people who are heavily investing their time into it so it makes sense.
It would probably be fine just for trying the system out and seeing how it works before you invest though.
The GP was asking for a comparison the odds/cost of mining a coin with the odds/cost of winning the lottery. Not about "investing," and not about "making a profit."
Basically, which form of gambling is better from a cost/rewards perspective.
But again, not an expert. Just the articles I've read and people I know who mine bitcoin say you can't profit that way.
If you use a mining pool then you won't make a profit on a laptop. However if you were solo mining on your laptop, then there is a very small chance that you could win seriously big moola.
The reason people join pools is to make money even if you never personally mine a coin. In a pool you just get paid for your effort. This is why joining a pool with consumer hardware will always lose.
In this case we aren't talking about pools!
There is two things that can happen when you solo mine - you either "lose it all" (all money spent on electricity down the drain) or "hit the jackpot," (1 full Bitcoin all for you!)
At that level with a small hash rate its gambling, you're throwing some amount of money at it at the very, very tiny chance of a big payout.
Say, for example, there's a 1/10000 chance any one person will mine a coin on consumer hardware per every $100 in electricity. So you're buying a $100 lottery ticket where the payout is $17,000.
Of course you "can't make money like that," the vast majority of people will lose money, just like the majority of lottery players will lose money.
That said there is absolutely no need to be such a jerk about it.
I strongly recommend reading the Bitcoin white paper: https://bitcoin.org/bitcoin.pdf It is not as nearly as long and complicated as you would think, if you know the basics (what's a hash, how do public keys and digital signatures work). I found it way clearer than all the explanation articles I've seen on the internet.
but if you set up a handful (3-5) of high end ASIC miners and mine BCH (10x more difficulty/hashrate on BTC right now) without a pool for a year, there is a realistic chance you'll get lucky and mine a block (worth about $17k).
The numbers are changing all the time, but when I last did that calculation I was surprised.
I'm asking if I have $20 to buy Powerball tickets (with a chance to win $1 billion) or $20 to buy electricity for my i5-based mining machine, how do the odds compare?
Due to dynamic difficulty adjustments, the profit for miners is just a bit more than the cost of electricity. However, this is only true for those who have the best specialized mining equipment and the cheapest electricity in the world. For an average person living in a typical area, even with dedicated equipment, you'd probably be far under breaking even. Most likely much less than 20%.
And that's with specialized equipment (costing thousands of dollars). With your home computer, it'll be hundreds of thousands of times less efficient per watt of electricity to mine bitcoin. Even for other cryptocurrencies that might be resistant to specialized equipment, you'd still most likely be over 10x less efficient.
Go with the powerball tickets.
Mining Bitcoin using CPUs is unprofitable. They're basically gaining cents worth of bitcoins using dollars worth of electricity. See https://bitcoin.stackexchange.com/questions/41276/in-the-asi...
"Technically yes, economically probably not. If you run a blog that gets 10 visits/day, the payout will be miniscule. For the captcha and shortlinks with a sensible hash goal (1024–16384) you'll need to have a whole lot of users to make this worthwhile."
I do like it as an accessibility friendly captcha system, though.