See your turnover and your gain over the last 30 days on your Sello dashboard. You can also see and how it compares to your previous month. You can chose to include or exclude tax and shipping in your calculations.
Your turnover is based on your order total for the last 30 days. Your gain is based on turnover subtracted with the purchase costs of the products sold. In your account settings you can choose to have the calculations include or exclude shippings costs and include or exclude VAT.