Most search engine spiders don't index everything you embed in a web page. Flash, Java, Shockwave, graphics, and frames are a few of the roadblocks automated spiders run up against when parsing pages. Spiders don't read graphics or many embedded objects, but text is easily digested. Text is the universal language of spiders. Here are a few spider-friendly design tips to keep in mind:
Dynamic content Avoid the question mark (?) for dynamically generated content, as most search engines don't follow these links. CMS tools like Vignette Story Server (http://www.vignette.com) can generate pages without the query command.
Flash Flash content is not indexed; instead, only the alternate content or HTML page is indexed. Make sure that you provide alternatives. Flash MX addresses these accessibility issues to some degree.
Frames Some spiders don't support frames. Avoid frames, especially on home pages. They can degrade usability and slow page display.
Images Provide text alternatives for all functional images. Substitute styled text for graphic text where possible.
Structure Favor breadth over depth for site hierarchy. Spiders don't crawl more than two or three links deep, which means that sites with deep site hierarchies may not be fully indexed. Avoid splash screens because they add another level.
Hidden text Avoid using text that is the same color as the background. Search engines flag this common keyword " stuffing " technique.