Posted by webnauts
That is not always true. You should not use everywhere alt tags, or in some cases you should not use them at all.
Read my tutorial I published recently about the use of Alt attributes: Alt Attribute & Search Engine Optimization - SEO Workers

I read your article. Every image should have an alt tag. You do not have to put the same keywords in every tag but it is extremely important to use alt tags. You do state that it is good in your article and basically state that you shouldn't use the same keywords. The site is not over laiden with images and alt tags will not hurt the site.

Many times if I do not have images on a page I will alt the border images just to create links. Even if you put "left border in red at xyz" it gives the image importance in the search engines. Most sites do not spam the content with the site name. f the site name has keywords in it you can not get penalized for using them in alt tags. The alt tag lends crediblity to the image and would not be considered spaming if done right.