Links are a key element in search engine optimization. They function in two important ways. First, they are used by the search engines to navigate around your Web site. Second, they are used to determine popularity.
Links Around Your Site
The links that you have within your site that lead from page to page are used by the search engine to move around your site. If the search engine robots cannot follow the links, they cannot find a page to catalog it.
A rollover link functions by swapping out two images. When the page is first displayed on the screen the image for the "up state" is shown. When a visitor's mouse pointer passes over the image, that image is replaced with one for the "over state." You can see the effect in action by trying the link on the right.
Sometimes a search engines will also have trouble with image mapped links. Image maps are areas of an image that are "mapped" out by specifying the coordinates for hot spots. An example is on the right. Image maps do not involve swap outs.
Avoid linking problems by incorporating plain text links on all pages. Plain text links can be very simple, such as:
They can also involve customized Cascading Style Sheet rules, such as:
Either way, text links are not only easier for search engines, but they are also often easier for real people, too.
Friendly Incoming Links
One of the determining factors for the positioning of a Web site in the organic results is the apparent popularity of the site. One of the ways popularity is judged is by the number of incoming links. Incoming links are links that lead from other Web sites to a Web site. Outgoing links, links that lead away from a site, do not help ranking and may actually hinder it if the search engine thinks that the outgoing links are suspicious.
The diagram on the right illustrates the principle of incoming links. But, link direction is only one of the properties in which search engines are interested. The quality of the links is also considered.
The search engines put more value on good quality links than on links of poor quality. There are several factors that determine link quality. Included are:
- How closely the topic of the originating Web site matches the topic of the target Web site
- The appropriateness of the "anchor text."
Let's imagine that you have a Web site about deep sea fishing called www.superfishing.com. Some of the links are good, some are poor. We can evaluate the links by using the examples below.
Good Link: SuperFishing.com is a good fishing site
Bad Link: This is a really good site
Good Link: SuperFishing.com tells about my sport
Bad Link: SuperFishing.com is a site that belongs to my cousin
Good Link: You can find everything about fishing at SuperFishing
Bad Link: Find out about fishing here