You can get all sorts of information about your ticket sales through the Sales overview page.
When you log into your Billetto account, find your event in 'My events' at the top-left panel. Scroll down and click on 'Manage' next to the relevant event to be taken to the Sales overview page. Here you can see how much revenue your tickets have generated, and you can also see how many tickets have sold and how many you have still to sell. You can scroll down to see a graph charting your ticket sales over time.