Web Site Optimisation - Alt Tags and Link Text
Alt tag are not read by every search engine but some do take note of them. Accessibility equipment however needs alt tags to describe pictures, buttons and non-text links to the disabled user.
To make the alt tag useful for both accessibility and search engine optimisation it should be used wisely. The alt tag should describe the graphic while using a keyword that can sensibly be associated with it. Refrain from using large paragraphs or keyword stuffing as that can, and usually will, be considered spam.
Link text can be very important as search engines do take note of the words used in the anchor text to describe the page being linked to. As with the alt text (and every other aspect of professional search engine optimisation) link text should be used wisely and make sense to the viewer.
Using text for links instead of buttons, image maps or framed menus not only allow the engines easier access in spidering the site, it also makes it easier for the disabled.
NEXT Step: Search Engine Optimisation - DO NOT SPAM