Probably one of the biggest SEO mistakes that people are making today is not deep linking. There are hundreds of websites that have a good design and have a respectable PR on their homepage, but start to click around and you will find out that the rest of the site has as PR 0 or worse. This is a prime example of poor or lazy SEO, and so many people are making this mistake. It is understandable to have your homepage to have a high ranking, but don’t forget that your site is more than just one page. You homepage usually does not have the majority of the content that you want people to see anyway. Optimizing these interior or deep pages will benefit your overall rank in the SERPs and increase your PageRank across your site as well.
The objective of deep linking is to optimize specific pages on your website for the one or two keywords that they focus on. For example, imagine that you were a vet and had a page on your website for each type of animal that you treated i.e. cats, dogs, horses, etc. Now instead of optimizing your homepage for each type of animal you treat and optimizing for you being a vet, with deep linking you would only optimize your homepage for you being a vet (i.e. vet in “your-city”). Then you would optimize your page about cats, your page about dogs, and your page about horses separately. If your on-site link structure is setup correctly, this type of optimization will benefit your entire site because as your deep pages gain in PageRank, they will share that with the pages above them. Now instead of having a site where your homepage has a PR of 3 and the rest of your site is PR0, you will have your homepage PR3 and your deep pages will have PR1 or 2.
Deep linking will also make your site more user friendly. Say a person is searching for a horse vet and they come to your site. Now if you optimized your homepage for “horse vet” they will click your Google listing and end up on your homepage, only having to look around for your page about horses. Instead, if your optimized your page about horses for “horse vet” they will click your Google listing and immediately be on your page about horses. This provided instant satisfaction, which is what internet users want. This will increase your chances of converting potential customers into real customers.
There are some instances where deep linking is not necessary. These would be for pages you don’t necessarily want people to see like a “terms & conditions” page, or pages that are not that important for users to see right away like a “contact us” page. Also, if you have a small site with just a few pages, deep linking may not be too important because your PageRank will naturally trickle down to your interior pages if you have the right setup.