This is the scenario when a fairly new website drastically drops in the Google search rankings and is unable to get decent rankings for a lengthy period of time. There is debate as to exactly how the sandbox works or whether it even exists. This is because not every new website ends up in the sandbox. If you prove to Google that your site is worthy of trust & rankings, you can usually retain early rankings. This trust is usually gained by trusted backlinks, but there are other factors such as who you link to.
Well in my experience I've never been sandbox, I'm sure it doesn't even exist anymore. I've had the Google dance many times but sandboxed, never. And I've built 100's of links a day to brand new sites and no sandbox ever.
The sandbox still exists, and I can tell you why you are not getting sandboxed and they are. Most people think you well get sandboxed if you get to many links to fast, WRONG! You get sandboxed when you get to many links really fast and then you stops and you don't get anymore links for a few days or even weeks. That looks unnatural you get 100-200 links in the time span of 1-2 days then you don't get anymore for weeks. The way to now get sandboxed (which I am assuming you are doing), is to get a natural flow of links everyday. Meaning you could get 1k links a day and not get sandboxed, as long as you get 1k links every single day.
"You get sandboxed when you get to many links really fast and then you stops and you don't get anymore links for a few days or even weeks." Maybe but not in my experience, I've had the Google dance before many times, but my sites always come back in about a week or two, and they come back stronger than ever. Even when doing shady stuff like blog farming I still come back.
Thats what a sandbox is you fall of the serps then in a few weeks (Sometimes even months) you come back even stronger.
I have a site which i am certain has been thrown in the sand box, and i havent been able to get it out. it was one of the first sites i built and at the time i knew very little about SEO and stupidly paid for a submit to 30,000 search engines and directories deal. Im certain this is what got it sand boxed. Ive tried hard to revive it, it re appeared in SERPs on page 2 after i got a some quality back links, but it keeps disappearing again. my other 2 sites that i built at the same time, both rank well. Can anyone suggest how i might revive this site, ive been link building steadily for a few months.
Many times I feel google dance where one day my website s on the first page while other day in another page. The only solution I know for google dance and sand box(if it exists ) is continues link building (Better less number of links per day). The slow link building will give you ever lasting result. Any aggressive link building may cause trouble.
The sandbox is where google sends new sites to play while they grow and become "credible". All new domains will hit the sandy box when they start getting some traffic. You can fly under the google radar with a new site if you are not going for a lot of traffic. However, its best to just get in the box and wait it out. It can take a few months to a year. Solid PR links to your site should (in theory) limit the time your site will spend in the box.
Try to get out of the directories again? Seriously, that would be a new market, de-directoring web sites! SY