How do I determine the sales of just pre-order products?

To determine the sales of just pre-order products, and not include in-stock items, here's how: 

1.) Go to your Purple Dot dashboard and click the Pre-orders tab. 

2.) Click 'Download pre-orders'

3.) This will download a CSV that includes data for all previous orders. 

4.) In the spreadsheet management software of your choice, you can filter the column Line Item Type to Pre-order and can sum that column