Just random thoughts. When checking the Google cache plain text mode, noticed a "click here" comment on my webpages, which I certainly hadn't placed there. Checking into this - some of my advert html tags have a noscript option, and an alt text "click here" for the images. Now, subject to permission from the advertiser/ad agency - there could be a slight optimisation opportunity there to edit those alt texts in the adverts to something a little more useful. Just a thought.
Its not a 'slight' opportunity. Its a real big one !! Case study: Statcounter.com Provider for free web statistics. They use a <noscript> portion where there is a link pointing from an image to statcounter.com with link text like 'free visitor counter' , 'hitcounter' etc.. You search for these keywords in google, they are in top positions !! Enjoy..
Thats just a huge waste - using a good keyword phrase will give your a better leg up when it comes to the alt tags for images.