Metrics. Typically, the chart defaults to showing the visits metric, although there are some exceptions, such as the Pages report, where pageviews are shown instead. Not all metrics are available with all reports, although you can generally get around this limitation by creating a custom report.
- Compare Two Metrics. Sometimes it’s useful to compare two metrics. Let’s say you’ve noticed a drop in page views recently, but you haven’t seen a similar drop in visits or unique visitors. What’s up with that? If you compared both visits and page views for the last several weeks, you might see where the problem is. Were they both tracking beautifully for a while, and then suddenly — one day — page views dropped? Was that the day that you redesigned the home page? And perhaps forgot to add the Google Analytics tag to your new design?
Granularity. This is a fancy term for “hourly, daily, weekly, or monthly”. This switch is especially helpful when you’re trying to eyeball trends. If you change your date range to several months, for example, switching your granularity from “daily” to “weekly” will simplify the visual enough to help you see if and when things are going well or badly.
Y-axis. If you are looking at only one metric, the values will appear on the left vertical axis. However, if you’re comparing metrics, you’ll also see an axis on the right. Google Analytics automatically scales each set of lines to their respective axis, which can be confusing sometimes. In the chart above, for example, it appears as if page views are actually trailing visits — statistically impossible. When you see the different axes, however, you see that the page view axis tops out at 4,000 while the visits axis tops out at 3,000. Ah, now it makes sense.