I have heard a lot of buzz regarding Google sandbox. The said that new websites will get sandboxed for a couple of months. This is because these sites still do not have inbound links. Aside from that, when Google thinks that the website is doing some unethical things or it is not good at its performance, it gets these sites into the sandbox. I also heard some people say that MSN and Yahoo are also planning to get their own sandbox system. The search engines will have to decide, through the quality of backlinks, if a website needs to ne sandboxed or not.