Inbound, Outbound, and Cross Links

The links on your site constitute a very important part of how Google and other search engines will examine, analyze, and rank your pages. Links can be categorized into inbound links, outbound links, and cross links:

• Inbound links point to a page on your web site from an external site somewhere else on the Web

• Outbound links point from a page on your site to an external site somewhere else on the Web

• Cross links point between the pages on your site

Broken Links

Broken links are links that do not work, either because they have been miscoded or because the pages they point to don't exist (perhaps it has been moved).

It's quite important to a search engine that none of the links on your site are broken. It shouldn't be that big a problem to go through your site and check to make sure each link works manually. Doing this will also give you a chance to review your site systematically, and understand the navigation flow from the viewpoint of a bot.

Even though you've checked your links manually, you should also use an automated link-checking tool. Quite a few are available. A good choice is the simple (and free) link checker provided by the World Wide Web Consortium (W3C) at http://validator.w3.org/checklink. All you need to do is enter the domain you want checked and watch the results as the links in your site are crawled.

Inbound Links

You want as many inbound links as possible, provided these links are not from link farms or link exchanges. With this caveat about inbound linking from "naughty neighborhoods" understood, you cannot have too many inbound links. The more popular (and the higher the ranking) of the sites providing the inbound links to your site, the better.

Inbound links are considered a shorthand way of determining the value of your web site, because other sites have decided your site has content worth linking to. An inbound link from a site that is itself highly valued is worth more than an inbound link from a low-value site, for obvious reasons.

Outbound Links

The "everything in moderation" slogan is really apt when it comes to outbound links. You could also say that the "outbound link giveth and the outbound link taketh." Here's why: you want some respectable outbound links to establish the credibility of your site and pages, and to provide a useful service for visitors. After all, part of the point of the Web is that it is a mechanism for linking information, and it is truly useless to pretend that all good information is on your site. So on-topic outbound links are themselves valuable content.

However, every time your site provides an outbound link, there is a probability that visitors to your site will use it to surf off your site. As a matter of statistics, this probability diminishes the popularity of your site, and Google will subtract points from your ranking if you have too many outbound links. In particular, pages that are essentially lists of outbound links are severely penalized.

If you follow the word-per-page guideline I make in "Words and Keyword Density"a little less than 250 words per pageyou'll get best results if you try to provide at least two or three outbound links on every page and no more than ten or fifteen per page

Cross Links

Cross linkslinks within your siteare important to visitors as a way to find useful, related content. For example, if you have a page explaining the concept of class inheritance in an object-oriented programming language, a cross link to an explanation of the related concept of the class interface might help some visitors. From a navigability viewpoint, the idea is that is should be easy to move through all information that is topically related.

From an SEO perspective, your site should provide as many cross links as possible (without stretching the relevance of the links to the breaking point). There's no downside to providing reasonable cross links, and several reasons for providing them. For example, effective cross-linking keeps visitors on your site longer (as opposed to heading off-site because they can't find what they need on your site).

One reason for cross linking is that ideally you want to have dispersal through your site. You may have established metrics in which one page that gets 100,000 visitors is doing well. In this case, 100 pages that each get 10,000 visitors should be considered a really great success story. The aim of effective cross-linking is to disperse traffic throughout the pages of relevant content on your site.