Hi!
There are benefits of deep linking in SEO. When getting backlinks for your website, you cannot have them all coming in to your homepage. That way the other important pages like product or services pages will be completely ignored by the SE’s and as a result, they will never get much. traffic either. So you should point your anchor links to your important products pages when working on backlink strategy. 
It’s also important to remember that most web surfers have an attention span that makes a bluebottle on speed look dedicated and persevering. When people follow a link from Google to your website, you have a very short timespan to hook them in before they give up and go elsewhere. If all your users are landing on your home page, no matter which actual content page is relevant to them, then you’ve got a problem - you can only highlight a certain number of products/services at the top of the home page. So the chances are that, for a lot of people, landing at the home page won’t give them an immediately obvious route to the page they’re after. And when I say ‘immediately’, I mean ‘immediately’. If it doesn’t leap out of the page and grab them by the throat, you’ve lost a significant chunk of potential customers already.
Whereas if you encourage deep linking, there’s a much better chance that the googler will land on the page that actually answers his question or provides the service that he wants.
Deep Linking helps pages other than the home page to rank for their targeted keyword phrases.
Deep linking also builds authority. Google sees sites with lots of links to lots of URLs as MUCH more of an authority than sites with almost all of those exact same links pointing to their home page.
If you think about the definition of authority, it means that you know a LOT about a lot of areas within your niche. Since each page on your site should be about a different topic within your niche and be targeting different keyword phrases, links to lots of different pages on your site would imply to Google that lots of other webmasters think you know about a lot of topics within your niche… i.e. your site is an authority within your niche.
Really true and agreed with u all…
Deep links really matters and does work for a site as far traffic as well as ranking to all the pages on the site is concerned cz if all backlinks only points to the homepage, other pages, if possible, might not get enough traffic.
Deep linking really work in SEO. It always help to put your inner pages also in the good ranking of search engines which automatically promote your home page as well. 
Deep linking, just like other kinds of links, is a vote pointing to your website.It is linked to an inner page of the website.
Main benefits of deep links are:
1)Deep links improve traffic for the site.
2)Deep links can build relevance for your site.
3)Link Juice:The more the number of incoming links to your inner page the higher the rate of link juice transfer from your homepage.
4)Through Deep links we can rank for additional keywords.
If not for the deep connections were, your visitors never got a chance to exceed your home page. Well, it certainly does not mean that your site does not have good content, but all I’m saying is that people simply do not have a way to get access to everything “good” content if you do not use deep links. Once you have entered deep links, you will be able to identify which pages are most viewed by visitors, resulting in more conversions. In short, you understand your entire site using deep links
But what to do when some forum’s dont allow linking or promotion ? Then how to link on that site ?
you can’t
move on
Just share information.
Visitors will visit your profile and hence visit your website.
Deep linking work in SEO very well . It always helps to put your internal web pages fir getting good rank in search engines which automatically promote your homepage of website .
It helps you to rank your inner pages higher in SERPS
If that was your intention of joining a forum than you’re doing nothing but spamming that forum. You may get a poor-quality link or two from a forum, but your sites reputation will nose-dive due to your dirty tactics at promotion.
Deep or Inbound link building are used to increase the traffic for the inner pages. Deep linking makes the website more user friendly and thereby increases the popularity of website. It determines the page rank flow within the website.
That’ll do folks, thanks.
Thread closed.