A pie chart is a good choice when you are trying to compare parts of a whole. Numbers are shown as percentages of the whole. Pie charts cannot show data over time. A pie chart may be useful to show a breakdown of sales by publisher or new to file vs repeat sales. You must select one category and one metric for a pie chart to be displayed.
Affluent will not show slices with a value of less than 4%, they will be grouped together and displayed as "other". So, if you have 100 promo codes that each account for 1% of your revenue then the pie chart will just be a single slice labelled other.
To show your data in a pie chart, select "Pie Chart" from the drop down menu under the title of the report.
Pie chart not what you're looking for? Check out the other options: