Hidden text and hidden links are big trouble and something you should never do in SEO.

Hidden text may contain keywords which has the same color as background. Search engine robots would follow a hidden link which is not visible to the nacked eye.

A hidden link might be a graphic which is very small(may be only one pixel by one pixel) and the color is the same as the background.

If a search engine detects text in the same color as the background, it might penalize or even ban your site. Frankly, we were told by one search engine expert that if you put a black table on the white background and, but the text is white, your text would be taken as hidden text because of the white background and white text, no matter the fact that the text is completely visible in the black table.

Doorway pages are also bad. Usually there is just a link to another site or auto redirect. doorway is page prepare for search engine but not for human.

By the way, “doorway pages” are different with “entry pages”. You can get lots of my traffic entering through one or another of my articles. But these are real articles with real content, designed for human eyes and optimized for the search engines. It’s very good, cause it put contents on website,and se like contents.

Duplicate pages are not suggested. Search engines like original content made for human visitors. if you post articles with little changes to file pages, you might be considered as spam.

You can choose proper keywords for your site and the optimize the site according to it, but not to cheat the search engines? It probably will cost you less to hire a Search Engine Optimization expert, and your website will not get banned.And those 10 seo tips are very useful, I highly commend have a read of those tips.

Hidden text may contain keywords which has the same color as background. If you spend much time on the Internet, you’ll be approached about many others sooner or later.