Edward Tufte has long claimed that pie charts are entirely useless. The polemic linked in these images and below argues that there are cases where not only are pie charts useful, but they are clearer than bars or other types of charts. Consider the images above: when comparing individual segments, the bar chart is clearly superior and makes comparisons elegant and simple. However, if the intended point is to show that companies B and C control the majority of the market, then a pie chart is enormously effective. Click through for a well reasoned championing of pie charts.