Rand's philosophy is not about economics - it's a complete system, with distinct metaphysical, epistemological and moral positions, all of which give rise to applications in politics, art, science and other fields of human endeavor. (Not unlike Aristotle.)
Here's the citation for Atlas Shrugged being only 2nd to the Bible in popularity: http://webcache.googleusercontent.com/search?q=cache:U54zOrN...