Someone has been selling 2 GH/s CEX.IO vouchers on eBay for a couple of dollars each. Apparently these don't ever expire meaning that they continue hashing and hashing and hashing forever.
Now, my question is, why is this not a good deal? Isn't the potential reward infinite? Wouldn't it make great sense to spend a finite amount of money to get something that gives an infinite amount of money back?
Before you jump in, consider these:
1. You may earn an infinite amount of BTC, but it will take an infinite amount of time to do so.
2. Right now, 1 GH/s at cex.io earns about $0.008 per day (less than a penny). How much are you willing to pay for that?
3. The amount you earn will get smaller and smaller, halving every 4 months or so.