Wikipedia says that a tag cloud is a visual depiction of the tags (topics) on a Web site. The tags are usually listed alphabetically and font size or color is used to show the relative importance of a tag.
But first, let’s talk about tags. The choice is tags is incredibly important on a Web site or blog. Your tags should represent what’s important to you and your target audiences. Personally, I think you should limit your tag universe to a couple of dozen topics so that you can focus your content and visitors can easily grasp what your site is about.
So once you’ve got your tags, you’ve got to tag every piece of content. Yes, it’s extra work but it will pay off. With tagging, you can display related content and of course, you can have a tag cloud!
Take this blog. You’ll see from the tag cloud on the right that the tags with the most number of posts are: marketing, social networking, blog, leadership, Google and Twitter. It’s great for me to see the topics I post about most frequently and I can easily see if I need to post on other topics so as not to bore my readers.
But the most interesting thing about tags is how they connect people. Here’s how: on a social bookmarking site like Delicious, I can see how many other people have bookmarked the same pages. On my list, for example, I can see that 421 have saved The Cult of Done Manifesto in their bookmarks; I can also see their comments, and their tags for the same site. I can click on the Delicious profile for any of the users or click on any of their tags to see what they’ve saved under a specific topic. 2017 update: RIP Delicious.