As you gather feedback to improve your services and engagement levels with your customer base, you gain insights into the preferences of your guests. If you gather data from the early stage of your business, you can start seeing trends in how your guest's rate you over a period of time. You can then further analyze the reasons behind any fall in ratings, or if the ratings steadily improve, you can be assured that your business is headed in the right direction.
From this bar chart, you can view the average feedback you got for each month across the selected services for the selected time period. The darker the bar, the more the number of invoices on which you got feedback.
For example, from the above screenshot, in May and Aug, your business got the highest number of responses for your feedback questions, while July was the month in which very few guests responded to your feedback questions.