Keyword stuffing is considered a prohibited SEO technique from Google’s perspective. As part of this technique, keywords are very often repeated in metadata, in textual content, or link text to increase the keyword relevancy artificially. Keyword stuffing results in a significant increase in keyword density and is labeled as spam by search engines, which usually results in the devaluation of the applicable page.
In the early days of search engines, the 1990s, their work primarily consisted of sifting through a fixed index of websites for specific keywords and combinations. So while the search engines were still relatively simple, (today this would be somewhat equivalent to the level of search functions available on websites) the website, which had a strong linking structure and included the searched keyword as often as possible, was favored. Thus, the door for spam SEO was wide open and high rankings were able to be achieved with relatively simple methods. Keywords were consequently “stuffed” wherever possible, including in the metadata and the source code.
Once the search engines algorithms had been repeatedly refined and once important metrics such as keyword density became secondary factors (only as a warning that the keyword density must not be too high and not go over the optimization goal), keyword stuffing finally went out of fashion and is now considered a spam measure which does not even lead to short term success.
In keyword stuffing it is assumed that the relevance of a site for a specific keyword or keyword combination increases if that exact keyword or combination is particularly frequently used on a web page. Different variations of this method abound. Keywords are “stuffed,” wherever possible:
From Google’s point of view, one should avoid keyword stuffing (filling up one’s pages with keywords indiscriminately) because it can be extremely detrimental to the ranking of the page. The user experience may deteriorate significantly since the text is no longer readable due to the frequent use of the same keywords and becomes irrelevant to the user. Google recommends creating valuable content for website users and not to focus on tricks such as hidden text or other unauthorized techniques. Since the Penguin update, Google is actively working to combat this technique and tries to identify and penalize pages recognized by the algorithm.
Keyword Stuffing has no positive SEO effect. To do on-page optimization today, webmasters and SEOs should pay more attention to the semantic context of content on the website and focus less on keywords. Because of the constantly improving search functions including the Google search (Hummingbird update to name one), and since comparisons are also possible with the search bar, techniques such as keyword stuffing can be compared to athletes who dope for enhanced performance right before a competition and then act surprised when they are discovered.
That keyword stuffing does not work anymore has a positive effect for the SEO industry because it brings it out of the “sleazy corner” and makes it clear once again that when it comes to search engine optimization it is not about dirty tricks and scams, but real skill, experience and knowledge.
Google is able to distinguish unique content from copied content, thin content, and web spam better and better. The gibberish score helps with that. Google even got that patented in 2009.