Mh, somehow I'm wondering about the algorythms and validation... Will the algorythm really understand which use is ok? Mh, I'm not that sure about that ... I'm not into parsing html ;)
In the first case, we have a genuine application of hidden divs, that are made available to the user, once he does something. Take heed though, that not
everyone has JavaScript enabled, so you might miss some customers. They will never get to see the product descriptions, save you provide the swapping via server side means (via asp, jsp or php for example).
In the second case, there is definitely
SEO at work, and it's arguable if you get yourself banned for that practice... I wouldn't recommend it, but I'm no professional
SEO whatsoever, .. yet I'm focused on delivering maximum usability for the human user. Read through google's infos on SEOs ;) they're quite interesting to read...
So if you cease using those non-userfriendly
SEO practices, you may not be maximizing/optimizing to the best degree for the robots, but you can be rather sure, you will never get banned and the google updates would never have an alltogether bad impact on your site. Since you're not using any bad practices, that is...
just my two cents,
Georg
(Remember, I'm no
SEO, so I probably can't be taken too seriously I guess) :)