Link bait works best if you have a blog and are in a niche that has a lot of other bloggers. Linkbait is simply a way of talking about something controversial or having a controversial opinion. When other bloggers and webmasters notice your post, they may link to you because they want to share their opinion as well. You'll likely get a lot of comments from readers agreeing and disagreeing with you.
Keep in mind that not everyone is going to like what you have to say, and you might get some flak. As long as you can back up what you're saying, you'll probably gain respect from both those who agree and those who disagree. At the same time, you may see an increase in your sign-ups!