My Search Engine Rankings have dropped recently - Why?

There can be many reasons behind search engine rankings being dropped as mentioned below.

SPAM Techniques used in Website
You may have used hidden text, doorway pages, duplicate content on various web pages of the website, cloaking, over optimized web pages etc in your website. Search engines don’t like this.

So, remove all hidden text elements from your website or rewrite those & make it visible. In case of doorway pages, remove it or rewrite those pages with proper look & feel, having different title & meta pages for each page, variance in content for each doorway page, limiting outgoing links to 40 per page & remove keywords stuffing content. Cloaking should be avoided completely. For Over optimized web pages, remove extra stuffing & repeating words, keep keyword density upto 3-4% & place targeted keywords at importance parts of webpage properly.

If you have web pages that contain similar content then remove those pages which are not of relevance OR rewrite all those pages targeting different keyword per page making sense to visitors. Idea behind is not to repeat same content & speak differently.

Major Changes done in Website
If you have done any major changes in your website content recently then it is likely that it may affect your current search engine rankings. If you wish to retain those rankings, then make minor changes in existing content and add related content for new targeted keywords, if possible.

Incase if you have made changes in site structure, web page URLs or webpage name then again it may affect search engine rankings. It is because of some external web pages may have linked to a particular web page of your website, which is no more available or because of path changed. In such a scenario, care should be taken in redefining a new site structure & what impact will it create. E.g. 1) For web pages that already have PR, it is advisable not to make any changes in URLs or page name. 2) Those webpage(s) submitted by you to different search engines & directories, it will be good if you don’t change path. 3) For all paid or banner links available on your webpage, it should not take a risk unless you know what you are doing.

Server related problems
If your server remains down or experience downtime more often, then you lose visitors. Not only that, search engine crawlers may fail to index your webpage(s), if it visits on the instance when your server is down. Such instances may lead to dropping of search engine rankings. So, select a good, reliable web hosting vendor that listens to your server related problems & responds promptly.

More & More websites
Adding of new websites every day increases your competition particularly if it’s related to your industry or site theme. In addition to this, routine updates & changes made by your competitors may give you a pinch. Plus, changes that happen in search engine algorithms makes it more difficult. Under this scenario, keep a close look on all these changes and react strategically.

Source: Web2Promote - An Internet Marketing, Web Promotion and SEO Guide