Google Advertising Tools, 2nd Edition

Linking

The links on your site constitute a very important part of how Google and other search engines will rank your pages.

Links can be categorized into inbound links, outbound links, and cross links (see Figure 4-10):

Inbound links

These links point to a page on your website from an external site somewhere else on the Web.

Outbound links

These links point from a page on your site to an external site somewhere else on the Web.

Cross links

These links point between the pages on your site.

Figure 4-10. It’s important to understand the distinctions among the three categories of links

Broken Links

It’s important to search engines such as Google that the links on your site are not broken. It shouldn’t be that big of 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. As you can see in Figure 4-11, all you need to do is enter the domain you want checked and watch the results as the links on your site are crawled.

Figure 4-11. An automated link checker goes through the hyperlinks on a page (or site) one by one

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.

PageRank and Inbound Links

Inbound links are considered a shorthand way of determining the value of your website, 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.

This concept is at the core of Google’s famous PageRank algorithm (see the earlier section Using PageRank).

Note

For information about the best approaches for generating inbound links, see Chapter 3.

The best—meaning most likely to drive traffic—inbound links come from:

• Sites that publish content that is complementary and related to the content on your site

• Hub sites that are a central repository, discussion area, or community site for a particular interest group

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 penalized.

If you follow the words-per-page guideline I made in Words and Keyword Density—between 100 and 250 words per page—you’ll get the best results if you try to provide at least 2 or 3 outbound links on every page and, in any case, no more than 10 or 15 per page.

Cross Links

Cross links—links within your site—are 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 it 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 offsite because they can’t find what they need on your site).