Link popularity is the total number of web sites that link to your site. This indicated how well is your presence in the web scenario, and that too in relevant category.
Link popularity is not the matter of number of back links, the quantity, but it is the measure of the quality links to your website
Increasing link popularity is also of the same importance as the
SEO work. Now, we know that it's not just the quantity of links, but also the quality. In other words, it's not just link popularity, but also link reputation.