Tumblr.com gives Famous Quotes as High Priority

Tumblr.com points at the use of Quotes as an indentifier of "Popular" rank.

Tumblr.com has categories, one of them is Quotes, this to me is a sign that quotes have a higher than normal valuation with search engines.

Tumblr Defined: Tumblr is a microblogging platform that allows users to post text, images, videos, links, quotes and audio to their tumblelog, a short-form blog. Users can follow other users, or choose to make their tumblelog private. The service emphasizes ease of use.