A search engines job is to give the most accurate and relevant search for a query. So naturally it would love to give a higher placement for a site that is popular. I'll explain that later. The common misconception about link popularity is, The more site I have link to me the better my link popularity. This is not always the case.
Search engines are smart now a days.
They can determine which sites are generally more popular in traffic and links and give more weight if these extremely popular sites link to you. Also major site in each industry give higher weight than sites linking to you from an unrelated place. So knowing that your link popularity will increase if you re linked from a high traffic and popular site. Submit to Dmoz Dmoz.org is considered an extremely popular site. A link on dmoz will get addition link backs on AOL, Netscape, and various other search engines will all count toward increasing your link popularity.