This widget comes in two forms, depending on whether or not you have the Web Extend scripts installed on your web shop.
With Web Extend
The widget shows you the open rates for your recent email campaigns, as well as the total number of purchases made and revenue earned which can be attributed to those email campaigns.
Without Web Extend
If you do not use Web Extend, the widget shows you the total daily response rates for emails, listed by the day they were launched (even if the response occurred afterwards).
You can also click through to the Trends page for a more detailed analysis.
How does this widget help me?
This is basically a snapshot of the Trends page, since it pulls data from the same source. It lets you keep track of your current level of engagement with your customers, as well as highlighting any anomalies which might require your attention.
For example, you might want to look at days that generated unusually high responses and try to identify what it was that caused them, or check the content of campaigns that received low responses and make sure there are no issues with personalized and conditional content that prevented contacts from receiving them.