   How much would you ask for?
  Let's assume that a website offers you the following deal: you download an executable and run it when your computer is idle. The executable itself is open-sourced, signed and guaranteed by reliable authorities to be spyware-free, and is designed to perform perfectly ethical grid computing for the website (protein unfolding, differential equation solving, and so on). The executable is allowed to write to a temporary swap file on your hard drive, must be allowed an internet access on at least one port, but is not otherwise allowed to do anything with your machine's operating system, file system or anything else. You may also interrupt the execution at any time. The web site offers you payment for running that executable. You are to be paid $X per billion cycles used (this means $X per second on a 1GHz machine) and $Y per gigabyte of bandwidth used. Payment is to be received through Paypal or some other well-known and safe internet payment system.What would be the minimal values of $X and $Y to get you interested in participating?   
  It depends on what the data is being used for. Personally, on a spare machine I use as an FTP server at home, I leave one of the protein folding programs running 24/7 because I don't care about the cycles on that machine and it doesn't use enough bandwidth to bother me. The only thing I get for doing so is a stats page on their server that says how much work I've contributed, and there are enough people that you're not going to find my except by accident.The main thing I'd be concerned about for such a program is being able to set limits - I don't care how much I'm paid for my bandwidth (unless it's an outrageous amount) as long as I can ensure the program wouldn't overload my connection and prevent me from using high-bandwidth applications on my other computer.Personally, I think using real-world units like cycles and bytes is a bad idea. You should pay per 'work unit' based on the actual problems. This solves two problems - first, it means that those paying to run on the system will have a better idea how much it will cost, and second, there is less likely room for problems to appear if somebody has a faulty timer on their system (or if the process switches cores on a system without the patch that synchronizes the counters on them, etc).   ;  It doesn't really matter what I'd ask for -- the promise of having any money at all would make tons of people sign up, even if the reward is significantly lower than the cost of powering the machine.Take a look at AllAdvantage or similar "get paid to browse the interwubs" deals: these used to be really popular even though the reward was nonexistent.   ;  Aren't a lot of the computer intensive math problems like differential equations useful for developing nuclear weapons?I'm not really sure, the hard thing about this is, to get to a point that I feel I would rather run your program to take your money, rather than run something like SETI at home, then we're four to ten times more than simply you renting a dedicated host on a box that is highly comparable to mine.Plus if you are renting out mine then you have massive security issues, checking that I'm not feeding you corrupt data, tracking my usages to figure out how much you owe me, dividing things up over a large number of different system specs.Building a dedicated cluster somewhere is likely a far more effective choice.Also for me, the bandwidth isn't an issue, my connection is an always on 10mbit line, and I rarely download anything but the odd large patch or reinstall a steam game.I would be more than happy, and willing to name my first born after you if you could get me $0.0002 for X for 2 years,...   ;  If it's enough to pay the power, I'd participate - everything above would be nice.The last time I participated in folding at home my board computer did not woke up after reboot ... the board was dead. I kind of fear, that this happens again. So I would want to lower the cpu-usage manually as I like.   