link popularity is the measures of quality and quantity of sites that link to a specific site on the internet. It is play an important role in the visibility of the website to the search engine. Getting links from other website can be the most powerful tool online.
With link popularity is meant; "what is the popularity of your link?" how many backlinks does it have, what is the PR of those links, what are the places you can find those links, what is the "anchor text" for it.
Link popularity is the number of links that point to your web site,link popularity can be increased by getting permission to have your link listed on popular web sites. Most search engines use link popularity as relevance criteria which increases ranking.