There is an interesting thread at Search Engine Watch Forums named Hidden Links On Colgate-Palmolive Site. SEOs are debating if Colgate Palmolive is using hidden links on it's site to spam the search engines. Go to http://www.colgate.com/app/Colgate/US/HomePage.cvsp and click on the link at the bottom that reads, "Click Here To View Other Colgate-Palmolive Products." It opens up more links, that in itself is not the hidden links, we are talking about. What I know want you to do is go to the text only Google cache of this page, you can see it here. Notice that there are more visible links available to be seen. Here is a side by side;
What We See:
What Search Engines See:
Basically, they are using CSS to style some of the links as normal text and other links, to look like they are normal links. Many many many sites do this. Either for SEO reasons or for cosmetic reasons. The question is, is this considered spam or against Google's terms of service?
Forum discussion at Search Engine Watch Forums.