This document provides an introduction to bubble charts. It explains that bubble charts can show the relationship between three variables, with the third variable represented by the size of bubbles. It then provides an example of how a media company could use a bubble chart to understand the relationship between search volume, social conversation volume, and revenue for different movie genres. Specifically, it shows search volume on the x-axis, revenue on the y-axis, social volume as bubble size, and genre as bubble color. This allows the company to see there is a strong correlation between search and revenue overall and that some genres have a better correlation than others.