There are two options to track your online sales. First go to your GoPhoto - CMS and login with your credentials.
On your dashboard you find 'Upload & Sales statistics'. Here you can see your online sales of that day.
Statistics - Upload & Sales
When you want to see an overview of your online sales over a different period of time go to 'Statistics - Sales' in the sidebar.
Here you can change the date and get an overview over a different period of time. You can view these statistics daily, weekly, monthly or yearly. The statistics show the amount of single photos or all photos.
It's also possible to see if your photos were regular buys or purchase with a coupon code.