Link Dumping is the Black Hat art of dropping a link to your site everywhere that is humanly possible for little to no money. Common link dumps include guestbooks, comment sections, and link exchanges. “If spamming links will bring down a site’s rankings, then I want my competitors to have spammy links. If they rank lower, I’ll rank higher.”, says QuadsZilla in his post.
http://seoblackhat.com/category/link-dumping/