The Long Tail search
A phrase coined by Wired editor Chris Anderson in an article published by Wired in October 2004, which later became a book published by Hyperion in July 2006. In his discussion Chris Anderson says The Long Tail is the theory "that our culture and economy is increasingly shifting away from a focus on a relatively small number of 'hits' (mainstream products and markets) at the head of the demand curve and toward a huge number of niches in the tail. Narrowly-targeted goods and services can be as economically attractive as mainstream fare." [Source: The Long Tail]
Based on this theory presented by Anderson, The Long Tail search expands on the theory that media and entertainment industries need to push the niche avenues of mainstream popular products. In search queries it is important to tap the main and most common search terms (the head of the list), but also all the keywords and queries that fall along the talk of the search; which are the lesser searched for associated and related keywords.