I had a business idea much like that when I was a kid. Send people to deserted islands and let them survive on their own for weeks. However, I assumed it would only be for the ultra rich. It's mind boggling to me that the rates are actually really cheap (because you're ostensibly renting out a whole island for a night): http://www.docastaway.com/pages/adventure-cottages-huts/list

The most isolation I ever found was getting dropped on an uninhabited island (well other than wild horses) and running around it for an hour. I would love to go on of these trips. I've always been fascinated with survival (Castaway seemed like a fun adventure more than a tragedy). I admit that the whole thing is rather silly if you stop to think about it, but that doesn't stop me from finding the idea alluring.

I have to agree that the name DOCASTAWAY is really dumb though.