My Site Has Been De-Indexed, How Serious Is It?

Hi guys, just a quick question.

I have a site which I have been building around 5 links to a day.

Anyway, the site has been around since april this year and content has been added every 3 weeks or so.

The site has now been de-indexed and nowhere to be seen on Google.

Does anyone know why this typically happens and what I can do about it?

Dont start worrying just yet chap. This has happened before on some of my sites with bing and google but checked back after a few weeks and they showed back up. I dont know why but hope this helps.

Probably you got deindexed because of the content

De-indexed or sand-boxed? there is a difference, to see if you have been de-indexed go to Google and search the following "site:yoursite.com" if that brings up no results you are de-indexed, if you get results you are sand-boxed. If you are sand-boxed don't worry just keep link building and you will come back. If you are de-indexed then the domain is just about useless with Google.

if you have in fact been de-indexed all you can do is go read up on Googles webmaster guidelines and see if you have broken any of their rules. It seriously takes a lot to get totally de-indexed. Normally you have to be caught doing total spam or some other violation.
If you have then correct any issues on your site and then you can request for re-inclusion to the index. Keep in mind though that theres no guarantee you will be back but you can at least try.

Kindly check through Google Webmaster tools for the problems in your site.
You must have definitely done a mistake on site, the links create no problem as you are doing those slowly.

It is your onsite problem, like over-optimization, cloaking putting keywords at places not required etc.

If you are unable to check it out, take help of a expert.