The first step in the SEO design process is to ensure that your site can be found and crawled by the search engines. This is not as simple as it sounds, as there are many popular web design and implementation constructs that the crawlers may not understand.
1. Indexable Content –
To rank well in the search engines, your site’s content—that is, the material available to visitors of your site—should be in HTML text form. Images and Flash files for example, while crawled by the search engines, are content types that are more difficult for search engines to analyze and therefore they are not ideal formats for communicating to search engines the topical relevance of your pages.
Images are a file type that the search engines have challenges with “identifying” from a relevance perspective, as there are minimum text-input fields for image files in GIF, JPEG, or PNG format (namely the filename, title, and alt attribute).
2. Spiderable Link Structures –
Search engines use links on web pages to help them discover other web pages and websites. For this reason, we strongly recommend taking the time to build an internal linking structure that spiders can crawl easily. Many sites make the critical mistake of hiding or obfuscating their navigation in ways that limit spider accessibility, thus impacting their ability to get pages listed in the search engines’ indexes.
Google’s spider has reached Page A and sees links to pages B and E. However, even though pages C and D might be important pages on the site, the spider has no way to reach them (or even to know they exist) because no direct, crawl-able links point to those pages. As far as Google is concerned, they might as well not exist—great content, good keyword targeting, and smart marketing won’t make any difference at all if the spiders can’t reach those pages in the first place.