There's been some discussions of similar (or identical) ideas:

http://news.ycombinator.com/item?id=194028 29 comments

http://news.ycombinator.com/item?id=462278 26 comments

http://news.ycombinator.com/item?id=2830122 33 comments

http://news.ycombinator.com/item?id=3219747 no comments

http://news.ycombinator.com/item?id=3286693 86 comments

http://news.ycombinator.com/item?id=3347468 39 comments

http://news.ycombinator.com/item?id=3702070 99 comments

http://news.ycombinator.com/item?id=3948126 1 comment