Deep linking is very useful

[MarcusWrite]

Make sure you have links coming in to as many pages as possible. What does it tell a search engine when other web sites are linking to different pages on your site? That you obviously have lots of worthwhile content. What does it tell a search engine that all your links are coming in to the home page? That you have a shallow site of little value, or that your links were generated by automation rather than by the value of your site. Here is an example of deep linking, in this case to my personal happiness workbook.

[2dragonsltd]

deep links expose more of your site to google for site wide indexing,

dont automate anything, do it manually and keep it unique

[eons]

I've never really thought about that.  But it makes sense that more links to more pages are great and it does send a message that you have a web site full of really good content.

Just wondering though, would it make sense to have incoming links to both your index page with the www, without the www and the index.html page if it all goes to the same page?

[SCarlisle]

But I thought directories only want the main page. I guess you can do that with article links.

[Yung Roger]

Well there are deep link directories as well accepting links of inner pages as well.
They provide more visibility of your site to search engines.

[telxcomputers]

Deep Linking really useful technique specially when we want to crawl each page of website, social bookmarking and deep linking directory best way to making deep linking.   

[Spiralxs]

Deep linking is doing back linking of inner pages of website. It help in high ranking.