Spam is the most important threat to natural search engines like google and yahoo, whose purpose is to provide good quality search results for search phrases or phrases entered by their users. Google's PageRank algorithm update ("BigDaddy") in February 2006—the final stage of Google's big update ("Jagger") that commenced in https://operational-efficiency31751.blazingblog.com/32851390/the-basic-principles-of-free-tool