Most search engines will use the amount of backlinks a particular website has in order to measure the search engine ranking, importance and popularity for that site. For example, Google PageRank system comprehends backlinks as if they were votes in a ballot box. Each backlink is a new vote. This has led many companies to use what people in the SEO industry refer to as linkspam. Simply put, this means that they use as many links as they possibly can with absolutely no regard to the original site it links to. It is just a way to fit as many links on the page as possible.
Link Bait on the other hand is different to website marketing as it requires quite a bit of planning and marketing. With link bait web masters don’t just throw arbitrary links all over their site in an effort to increase page rank faster. Link bait is more deliberate and what normally happens is that a site using link bait will use links that lead to something very interesting for a large group of people. For example, a Celeb gossip site might get a lot of hits depending on the demographic being targeted, or FB applications are another great form of linkbait.