Mirror Sites and Duplicate Content - Google has a particular aversion towards spammed web site content and Google penalties for mirror sites reflect this.

Search Engines have come a long way since web's beginnings. Back in old days it seemed like anything you typed in would ultimately show at least one or more pornographic web site. Well, luckily those days have passed us and getting indexed on search engines has become a necessity of doing business on Internet. In my experience with personally working on over 250 business web sites in last six years (an having them all indexed), I have accumulated a substantial list of techniques that work and don’t work. There are literally hundreds of things that will have a negative effect on your ranking. Below is a list of my top ten.

1. Have no html text on your home page.

Because search engine robots are still not able to read images (jpegs, gifs etc), you will be guaranteed to not get indexed - because there is nothing to index.

2. Have a 100% Flash driven web site.

Some search engines are now able to index certain parts of flash, but as a general rule of thumb flash sites do not get indexed.

3. Dump a bunch of keywords on your home page and change colour so they are visible to eye.

While there is no published standard, most online professionals agree that tricking search engines by adding a large number of keywords on your home page is bound to get you black-listed on search engines.

4. Create an automatic redirect that sends someone to another web site (from your home page)

If you code your web site so that when someone visits it, it will go to another page instantly - most search engines will ban you.

5. Rely solely on your Keyword and Description meta-tags.