Basically, the sandbox is when Google does not allow a new website to rank for a certain keyword. The theory is that a new website should not be considered to have as much quality as an older one. This site is placed in a type of “sandbox” for a few months.
According to the theory this only happens with certain keywords, however no one really knows what those keywords are. Therefore many new sites may be sandboxed, however what I also understand is that it does not happen very often.
So how can you tell if you have been sandboxed? Basically, your new site should show up within three weeks, if not then you may have been sandboxed.
The good thing about the sandbox is it gives people such as long term bloggers an advantage because their site is not shot down from some new site that is just not a good of quality. The bad is that if you are in certain niches and start a new site it may be sandboxed just because it is new. Below is a video with a little more information about the Google Sandbox:
So, what is your knowledge on the Google sandbox and your thoughts on it?