Link Farm

Link farms are websites packed with a large number of irrelevant links, and Google treats them as spam since it has always favored backlinks earned naturally. Websites that build spammy links through sources like link farms risk being penalized. Link farming used to work back when backlink count alone carried real weight in rankings, but that's no longer true: Google now weighs the quality and naturalness of backlinks alongside the number. Sites that still rely on it tend to get caught and penalized before long.