Keyword Stuffing

The repeating of keywords and keyword phrases in META tags or elsewhere.

Writing copy that uses excessive amounts of the core keyword. When people use keyword stuffed copy it tends to read mechanically (and thus does not convert well and is not link worthy), plus some pages that are crafted with just the core keyword in mind often lack semantically related words and modifiers from the related vocabulary (and that causes the pages to rank poorly as well). See also: Search Engine Friendly Copywriting - What Does 'Write Naturally' Mean for SEO? Keyword Suggestion Tools (see Keyword Research Tools)

Placing excessive amounts of keywords into the page copy and the HTML in such a way that it detracts from the readability and usability of a given page for the purpose of boosting the page's rankings in the search engines. This includes hiding keywords on the page by making the text the same color as the background, hiding keywords in comment tags, overfilling alt tags with long strings of keywords, etc. Keyword stuffing is just another shady way of gaming the search engines and, as such, its use should be strongly discouraged.