Link Bait: Link Bait is the practice of creating, formatting and targeting content in a way that will encourage a target audience to link back to your site. This builds quality links for your site, often through social media and blog sharing. Basically, content in the form of videos, articles, podcasts or interactive quizzes acts as bait to prompt others to link to your site.
Link bait may be cultivated by a webmaster or it may be an unintended result of ordinary content. Link bait is often controversial, attention-grabbing or outlandish to attract the most potential. Many link bait creators use anger-inducing messages to drive traffic.
Unpaid incoming links are highly valued in search engine rankings and can move a site up in natural search results. This means that link bait can increase traffic and boost rankings at the same time.
Even though search engines often look negatively on obvious or overly-deliberate link baiting attempts, they still rate sites positively if incoming links appear to be natural, meaning they happen over time and don't seem to have been an intentional result. To search engines, these hits mean that a website has an authority on the given subject and will be of interest to a search engine user.
In spite of controversy surrounding link bait techniques, they're still considered an effective form of online marketing.