We examine the recent information visualiza- tion phenomenon known as tag clouds, which are an interesting combination of data visual- ization, web design element, and social marker. Using qualitative methods, we find evidence that those who use tag clouds do so primarily because they are perceived as having an inher- ently social or personal component, in that they suggest what a person or a group of people is doing or is interested in, and to some degree how that changes over time; they are visually dynamic and thus suggest activity; they are a compact alternative to a long list; they signal that a site has tags; and they are perceived as being fun, popular, and/or hip. The primary reasons people object to tag clouds are their visual aesthetics, their questionable usability, their popularity among certain design circles, and what is perceived as a bias towards pop- ular ideas and the downgrading of alternative views.