Link building isn’t just one way to increase your search rank; without it, it’s nearly impossible to see substantial gains. There are two main things Google takes into consideration when sorting ranks for a given query; the relevance of a particular page, and the authority of that page. inbound-links

You will need both if you want to generate any substantial rank, so assuming you’ve targeted appropriate keywords, your main focus should be on authority. How is authority measured? Inbound links. They’re evaluated and considered in complex ways, but the bottom line is that without some inbound link-based strategy, your authority will remain still.