Spamming (as related to searchengines) is forcing unsolicited or unwanted web pages into a searchengine's database.

People that have learned how spiders work, also learned how to fool them. Although your site may be of high-quality content, if you use any of behaviors defined as spamming, it can be blacklisted.

For directories, spamming usually means choosing an inappropriate category, capitalizing all letters, or using marketing language.

For search engines, definition of spamming varies. The following list includes behaviors defined as spamming by the top six engines: inappropriate site titles, descriptions and keywords; repetition of keywords, same color text and background (invisible text), tiny text, submitting more than once in a 24 hour period, mirror sites that point to different URLs, and meta refresh tags.