Have your rankings dropped recently? Before you do anything, you should try to find out what has caused your ranking drop.

The better you understand the reason why your rankings dropped, the better you can prevent your website from future ranking drops. There are six major reasons for ranking drops:

1. Your website changes

Most webmasters update their web pages regularly. As long as the changes are only small, this won't have a big effect on your rankings. However, if you re-design your web pages or if you optimize a page for a new search term then search engines might re-calculate your search engine rankings.

Google even has a filter for changed web pages. If you change your web pages, Google will temporarily apply a filter to your sites. Details can be found here.

Required action: If you have web pages with high search engine rankings then you should change these pages with great care.

2. The links to your website change

If you have an old website with a grown inbound link structure then it's not likely that your site rankings will drop because of a link change.

If the links to your site are mainly paid links that suddenly disappear or get discounted by Google then the loss of these links can be enough to cause a significant ranking drop.

In addition, sudden changes in the linking structure of a website make your website suspicious.

Required action: If you heavily rely on paid links you might want to reconsider your linking strategy. Try to get inbound links that last.

Continually getting links is essential to keep high rankings. If you don't work on your links then your website will be replaced by better linked web pages in the search results.

3. The websites of your competitors change

Everybody wants to be on Google's first result page. For that reason, it's only natural that other websites will be listed better than yours if you don't react.

Many websites target the same keywords as you do. If these other websites have better content and better links than your site then it's only natural that these sites get better rankings.

Required action: You must offer better content than your competitors. Make sure that you offer many web pages that are relevant to your search terms and that you have better inbound links than your competitors.

4. Spam elements on your web pages

Search engines don't like spam. If search engines find out that you use cloaking, hidden text, doorway pages or any other spam technique on your web pages then it is extremely likely that your website will be penalized.

Required action: Remove all spam elements from your web pages. Just because your website hasn't been penalized yet doesn't mean that search engines won't find the spam elements in the near future.

5. Search engine algorithm changes

Search engines are continually improving their ranking algorithms. While most changes are rather subtle, some ranking algorithm changes can have a major impact on the rankings of your web pages.

Required action: Wait for some days to find out if the ranking drop is not just temporarily. Then optimize your web pages so that they reflect the latest search engine algorithms.

6. Technical problems

Your web server can be the reason for a ranking drop. If your website is down when the search engine spider tries to access your website then search engines cannot give your web pages high rankings because they don't know your pages.

Some websites display the correct web page in the web browser but the server returns an error code. In that case, search engines won't index the web pages.

Required action: Make sure that your website is hosted on a reliable server that has no downtime. Check the HTTP status code that your website returns.

Almost any website owner will see a significant ranking drop sooner or later. Don't panic if this happens to you. Try to find the reason for the ranking drop and then act accordingly.

Source:
http://www.free-seo-news.com/newsletter289.htm#facts

Great tips but I would like to ask about no 4 which related to spam element as how the spam element is not from us. It happen to my blog when the spam element always come thru ads syndication.

4. Spam elements on your web pages

Search engines don't like spam. If search engines find out that you use cloaking, hidden text, doorway pages or any other spam technique on your web pages then it is extremely likely that your website will be penalized.

Required action: Remove all spam elements from your web pages. Just because your website hasn't been penalized yet doesn't mean that search engines won't find the spam elements in the near future.

great post and rep added. nicely laid out.
one newb question - when you say

Originally Posted by ~ Cyberian ~

4. Spam elements on your web pages Search engines don't like spam. If search engines find out that you use cloaking, hidden text, doorway pages or any other spam technique on your web pages then it is extremely likely that your website will be penalized. Required action: Remove all spam elements from your web pages. Just because your website hasn't been penalized yet doesn't mean that search engines won't find the spam elements in the near future.

I've had google trouble lately, not appearing for a search on the domain name. All my domain sites are freely hosted (usually on blogger or googlepages), and they forward out of godaddy cloaked - just to avoid the ugly mydomainname.blogspot.com in the title bar.

Is this sort of cloaking bad in google's eyes? it seems pretty normal activity to me. Or are my inward links just invisible to google because they go to my mydomainname.com, rather than the actual page content (mydomainname.blogspot.com)?

i think density is also one of the factor which can dropped the rank