There are two ways to display metric activity in the time series: daily, and cumulative. You can use the toolbar icon to toggle between the two:

Daily view

By default, the time series displays the daily activity movement for the metric. This means the change in value since the previous day.

For example, in the screen shot below, we can see that Boys Noize gained 524 new social media fans on 2 December 2011, which was an increase of 77 less fans than the day before:

Cumulative view

By switching to cumulative view, you can see the total value for the metric over time. We can now see how the total level of fans for Boys Noize has increased:

Cumulative view can be useful for showing how an artist has grown in popularity over time.