List contacts based on Products/SKUs bought

This method takes the *deal line item properties* and creates a list of all customers who bought that SKU.

When making a list:
1. make a "contact based list",
2. then select "Line item properties"
3. then select the property called "Product SKU - Unific"
4. then select "Contains any of"
5. Then paste in the SKU you want to segment by"