Content is King, if you have a good article for your content you can submit it to article directories. After you are submitting your article on those directories, you can add your information on those directories by using your articles. So you can get free link by this which also builds your credibility and your popularity as a writer.
The other benefits of using link building service, you can afford free or the other ways of advertising. As the owners you can choose a relevant links for your website and blog, when you make it linked automatically it’s your free advertising. Beside that you can make the connections with others with your niche, and for this connection it might made some people recommend your website to their friends then your sales by partnering with other website also increase