Sparklines are tiny graphics that look like miniature charts, but fit in a single worksheet cell. Compared to charts, they're simplified and stripped down, with no gridlines, borders, legend, or callouts. Interestingly, these limitations make sparklines so much more versatile than their graphing big brothers. While a worksheet might feel overburdened with more than a couple of full-fledged charts, you can easily fill its cells with a dozen sparklines, while still keeping it clear and clean.
As you'll soon see, using sparklines is easy. Using them well isn't too difficult either, as long as you have a solid understanding of their proper role in life. The key detail you should understand is that sparklines are not a poor man's chart. They aren't intended to replace, simplify, or compete with Excel's charting feature at all. In fact, sparklines have a closer relation to data bars, color scales, and icon sets—the conditional formatting features you explored in the first half of this chapter.
Much like these features, sparklines are a way to give you an at-a-glance overview of your data and its significance. For example, a properly placed sparkline can highlight plummeting profit, a seasonal spike in orders, or an uncanny winning streak in the company bowling league. They might not give you all the details, but they can alert you to trends, patterns, and dramatic changes, without forcing you to perform a painstaking review of all the numbers.
Currently, sparklines come in just ...