Defining SEO Link Spam To Stop The Madness
Link spam has become a more vexing issue for search engines, basically because it's difficult to detect and there's no clear definition, according to Tom Pick.
Pick writes that for Web site owners, link spam represents emails requesting the recipient list the inquirer's site on their Web site. He explains that the challenge for search engines is they aren't privy to these emails. And in a link spam campaign, links from various sites with a mix of one-way, three-way and reciprocal, is often indistinguishable from a reputable link-building program.