Selling idle CPUs

I got an interesting idea today. Probably you would be glad if you could sell your idle CPU, right? Few giants in the software industry recently start selling computing server. This is like they will compute the information from given data and return it back to user. All they do is doing CPU intensive part for you. What if everyone can do the same business? At least if everyone can sell their idle CPU?

Probably you guys know about SETI. This is the largest distributed project looking for Extraterrestrial Intelligence. This is a very CPU intensive task and so that they build a large distributed system and any personal computer can join in this network and donate their idle CPU to compute.

Here we can build a similar type of distributed system which will be able to perform specific task on request and count the total CPU work done. Anyone can join that system and will be paid according to CPU work done by his computer. Your computer participates in this only if it does remain idle. So that normal work will not hamper.

All these tasks will be executed in a different sand box so that your computer is free from any kind of malfunctioning attacks. Computation intensive softwares are the good choices for this system but the bandwidth drawbacks still remain.