Historically, companies that monitor links to their websites haven't looked kindly upon inbound "deep links"—links to site pages other than the homepage or other top-level pages.

Some objected on the grounds that deep links cause visitors to bypass a site's main advertising or branding page. Others were concerned that visitors might not recognize that they are on a new site and so might interpret the linked page as part of the website that linked to it.

But the truth is that deep links can actually be really good for a website. Here are five benefits they provide.

1. Deep links improve your search engine rankings

If you are serious about optimizing your website, you likely know that inbound links can boost your site's search engine rankings. The more high-authority sites that link your way, the higher your site will appear in search results pages (SERPs).

Well, your rankings can improve even more dramatically if other sites are linking to a variety of your site's pages, not just the homepage. That's because search engines infer that content throughout your site is worthwhile and so the engines reward you by improving your standing in the SERPs. Also, having deep links implies you are getting links the natural way (editorial links) as opposed to paying for them. (A fair number of paid link services will perform link building only to your site's homepage.)

2. Deep links increase your site's traffic

If deep links can increase your search engine rankings, it's pretty much a given that they can increase your site's traffic. The higher your site appears in search engine results, the more people who will learn about it and visit it.

Moreover, those who find the site through a deep link are more likely to return to the site than those who find the site through a generic homepage link. That's because a deep link, being more targeted, is more likely to give people what they want.

If a blog mentions the new type of organic dog treat your online grocery store sells, for example, you're probably better served by a link directly to a page featuring that product than to your store's homepage. If visitors to your site easily find what they're looking for, they are more likely to return.

3. Deep links let you target different keyword groups

If more of your site's pages get inbound links, then more of your site's pages will get indexed by search engines. If more of your pages are indexed, more of them will be crawled during Internet searches. That opens up many keyword opportunities for your site. Instead of trying to cram all your site's keywords onto your homepage or another main page, you can target different keyword groups on different pages.

Again consider the online grocery store example: Your main keywords for a page about organic dog treats might be "organic dog treats," "buy organic dog treats," "organic dog treats sale," "organic puppy treats" and so on. Ideally, you have different target keywords for each different product page..

4. Deep links keep old content alive

Many company sites now maintain blogs as a way to engage and interact with readers and increase site traffic. Unfortunately, many of the older blog entries get buried within the site and are never read again. You can revive these old posts by linking to them in your new blog posts.

When you blog about something relevant to a past blog post, add a link. A reader might click on the link, read the old post, and link to it himself. Good posts can go viral weeks, months, or even years after they were written.

Another good way to keep older posts alive is by posting a monthly summary of the previous month's top posts, and linking to them.

5. Deep links can help you learn about and improve your site

Without deep links to your site, people may rarely get beyond its homepage. That doesn't mean your site doesn't have good content, it just means that people don't have an easy way of getting to it. Deep links provide a fairly effortless way to reach your site's various pages.

Once you have a substantial number of deep links, and a resultant increase in site traffic, you can really start benefiting from a Web or keyword analytics tool. You can see which pages people visit the most and which pages people spend the most time on.

That information can help you determine which of your pages are most appealing to readers or customers, and which can be improved. Determine which techniques attract visitors, and implement them on the appropriate pages.