Ask HN: How to build my own crowdsource/distributed computing?

I am looking to build my own network of crowd workers that will require installing chrome extension, and do some distributed computing.

The problem is Amazon is restricted to US and I don't know of other places where they will let users install a chrome extension (in chrome store) in order to do the job, so my only alternative is now to figure out how to build my own crowd to do the specific task.

Bigger challenge is, I'm not sure where to find people to join and work on my jobs, the thing that is special is that you can leave on your computer and get paid for the computation hours, so if you leave your computer on, and your computer is used for crunching lot of numbers, you get paid. You also get paid on top of that for manual user input. In total, I think I can offer people 1 bucks per computer per hour, depending on how many computers you have running available.