Here’s an idea I thought of a while ago. You have the storm botnet, which is apparently now capable of being the world’s most powerful supercomputer:

The Storm botnet, or Storm worm botnet, is a massive network of computers linked by the Storm worm Trojan horse in a botnet, a group of “zombie” computers controlled remotely. It is estimated to run on as many as 1,000,000 to 50,000,000 infected and compromised computer systems as of September 2007. Its formation began around January, 2007, when the Storm worm at one point accounted for 8% of all infections on all Microsoft Windows computers.

The botnet reportedly is powerful enough as of September 2007 to force entire countries off of the Internet, and is estimated to be able to potentially execute more instructions per second than some of the world’s top supercomputers.

Obviously, having a large supercomputer is big business these days. So what you do is have a legal version of this. Let’s say you sell computers at 70% of their real price. The only catch is that people will have to run this special software as part of the system. The special software is basically a remote compute client similar to Folding@Home or Google Compute.

Once you have sold enough computers, you essentially have a large army of computers at your beck and call, for 30% the price of what you would have to invest in otherwise. Of course, obviously someone else owns the machines, but while they are doing lightweight tasks such as checking email and chatting, you are folding proteins, running simulations and cracking ciphers.

Now here’s the best part of the deal: the most expensive part of a grid is not the hardware, but the electricity that it uses. And guess who’s paying this electricity! The customer, not you!.

So there you have it. A cheap, one-time cost for an everlasting free CPU grid. Awesome ainnit?

note: This idea is under this license.