Duplicate content is a major concern for all the people related to internet. Google also dislikes duplicate content and is always ready to penalize or black list a site with such content. SEO services providers also put in various techniques to fool Google. These techniques though effective have their own pros and cons. Not many people might be aware of the use of hash (#) for SEO to prevent Google from indexing such pages with a duplicate content.

 
This is an advantageous technique for search engine optimizers who want to prevent the search engines from indexing particular pages like pages with duplicate content. The trick is most useful for websites having huge quantity of duplicate content as the pages with the hash sign will be ignored by the search engines and also the backlinks for those duplicate content pages will be transferred to the main page which in the above assumption is www.seoservices.com. This makes the search engine optimisation more effective. As Rand mentioned the other applications of hash include ability to show limited content, canonicalization and management of affiliate links.
 
Nothing comes problem free in the same way the bad part of the use of hash is highlighted when used for large content which needs to be broken into sub parts. It happens in case of tutorials which need to be divided into sub parts to make them easy for the user to read.  For tutorials broken into different sub parts with a hash Google only indexes upto the pages which are not preceded by a hash.  But will pass on the link juice of the other pages followed by a hash to the main page. And if the main page has all the main keywords and is rightly written then it should not be a problem for the search engine optimizer.