Part of the problem is that most entities who use CPUs have more then they need. If you want to make money with your CPU then you need to use it either to produ

Part of the problem is that most entities who use CPUs have more then they need. If you want to make money with your CPU then you need to use it either to produce a good or service worth more then a few cents an hour. The issue is that everyone else also has CPUs, so whatever you do can't be trivial. At that point you're optimizing for the market of your good/service relative to it's cost, and not optimizing for CPU usage.