The Sandbox (a.k.a. Sandboxing or the sandbox effect or the Google penalty) is a name given to an observation about the way Google ranks web pages in its index. It is the subject of much debate—its existence has been written about but not confirmed and several observers state that they have observed the contrary.
According to the sandbox effect, Google temporarily reduces the page rank of new domains, placing them into what is referred to as its "sandbox", in an effort to counter the ways that search engine optimizers attempt to manipulate Google's page ranking by creating lots of inbound links to a new web site from other web sites that they own.
A "reverse sandbox" effect is also claimed to exist, whereby new pages with good content, but without inbound links, are temporarily increased in rank—much like the "New Releases" in a book store are displayed more prominently—to encourage organic building of the World Wide Web.
David George disputes the claim that Google applies sandboxing to all new web sites, saying that the claim "doesn't seem to be borne out by experience". He states that he created a new web site in October 2004 and had it ranked in the top 20 Google results for a target keyword within one month. He avers that "[n]o one knows for sure if the Google sandbox exists", and comments that it "seems to fit the observations and experiments of many search engine optimizers". He theorizes that the sandbox "has introduced some hysteresis into the system in order to restore a bit of sanity to Google's results".
In an interview with the Search Engine Roundtable website, Matt Cutts is reported to have said that there are some things in the algorithm that may be perceived as a sandbox that don't apply to all industries. Jaimie Sirovich and Cristian Darie state that they believe that, while Google does not actually have an explicit "sandbox", the effect itself (however caused) is real.