1) Link Farms
A link farm is a series of websites that were created solely for housing free links. These links point to sites that were submitted by their owners in an attempt to gain recognition. Sometimes, the link farm is a web of sites that interlink with each other.
Google won’t put up with these kinds of websites because they are trying to get high rankings for websites that haven’t earned those rankings through good content.
If you use link farms as a way to build PageRank (PR), you are taking a huge risk. Even if your website has great content, your website will still get penalized or banned because the engines figure that if you had good content you wouldn’t resort to tactics designed to manipulate the search engine into giving a higher ranking in the SERPs. (Search Engine Result Pages)
If someone tells you that they can build you hundreds or thousands of pages across different domains all linking to your website, heed my warning: Don’t do it. This is a link farm and it will cripple your rank as soon as Google or the other search engines discover it.
This SEO tactic may initially bring in results… but those results tend to fade and can result in Google removing your site from their listings entirely.
Also, every once in awhile, search your domain name in the search engines to see what sites are pointing to you. If you see anything out of the ordinary, such as websites or pages that are simply long lists of links, check into getting your links removed from those sites. They are hurting your site’s PR.
2) Doorway Pages
Doorway Pages are a form of landing page that is designed solely for the search engine and sometimes isn’t even viewable to the human visitor. These pages sometimes use a redirect script that automatically points the visitor to another page on the website without the human visitor ever seeing the doorway page. This is known as cloaking and is definitely considered an illegal practice by Google and other search engines.
The only time a landing page is acceptable by search engines is if it is in the form of an informative, well written article that human visitors can read and enjoy, and they are not being redirected to the website’s main pages.
3) Keyword Stuffing
Also known as Keyword Spamming. One of the original illegal SEO techniques, keyword stuffing occurs when you load a webpage full of particular keywords, either in the meta tags, other script tags, or in the content itself.
This is different from optimizing the page for particular keywords because the same words are being repeated dozens or hundreds of times in no credible or informative way.
Keywords are hidden several ways, for instance some people will make the text the same color as the background so search engines see it, but no human visitors can. Others will hide keywords in script tags. Still others yet will use CSS to position keywords outside of your visible screen area, again so that no human visitors can see it – but search engines can.
At first, using such techniques might sound like a good idea. However, search engines can detect whether a keyword is being used properly and will penalize or ban your site for using any of the above techniques to stuff keywords into your site.
Oftentimes, the only way you can know if your site has been stuffed with keywords is to view the source code of your website (visit your site in your favorite browser, click “View” and then “Source Code.”) A page of HTML will display. If you see the same keyword repeated hundreds of times, then your page has been stuffed and will be considered in violation of every search engine’s rules.
4) Scraper Pages or Auto-Generated Pages
Scraper pages are those comprised of search results or content automatically pulled from dozens or hundreds of websites or search engine results. This is a form of plagiarism as no part of the scraper page is original content.
Most often, such sites are used to display Google Adsense Ads or other ads that pay the site owner every time a visitor clicks on it. However search engines have gotten very good at banning such sites from their results and human visitors can detect them easily as well.
Scraper sites are easy to spot … They are snippets of other webpage content, or search results, and don’t make sense.
These tactics listed here will surely get your website in trouble if you use them. Most of the SEO professionals know better than to use anything I’ve mentioned here, because they are all well-known “black-hat” tactics and they don’t work anymore. The search engines are getting smarter everyday.
It is always better in the long run to just load up your page with good content.