This isn’t a hidden fact; link building is the missing piece of most online marketing plans. Onsite SEO and content are just part of the game, but there is no part of code you can change that will have an impact on ranking like good, strong, focused links to your site’s pages. Naturally, link building is the one thing we all hate doing. Most SEOs, when you mention link building, will either groan and put their headphones back on, or just cry. But it is a necessary part of SEO.