As an analyst, I find that the difference between 24% and 25% rarely matters in practice. Pie charts are useful for showing that big differences are big, and th

As an analyst, I find that the difference between 24% and 25% rarely matters in practice. Pie charts are useful for showing that big differences are big, and that unimportant things are unimportant. Most other uses require a notion of absolute size of the pie in addition to breakdown, which can be communicated in a pie chart, but it's harder.