What is Google sandbox effect?
There are three theories explaining Google Sandbox Effect,
The first Theory said that Google puts ranking for all new websites in a holding tank until the new website can prove its ability to exist for (x) months, after that period which will be from 90 to 120 days the website ranking can commence.
The second theory said that not all new websites will be effected by Google sandbox but only new websites that built a large number of backlinks in a short period of time where Google suspected that this website is trying to get backlinks from link farms or pay it.
The last theory believes that there is nothing called Google sandbox effect and it is just a result of a mathematical algorithm rather than a decided policy.
Now regardless of interpretation, it is widely accepted that new websites takes longer time waiting for Google ranking than other search engines.
The only advice that we can give is never give
up, check your website for bad neighborhood using this
tool, and continue building good quality relevant backlinks.