There are several ways to collect past purchase data:
eCommerce Platforms: Most eCommerce platforms have built-in tools to track customer purchases. Customer Relationship Management (CRM) Systems: CRMs can store detailed records of customer interactions, including purchase history. Point of Sale (POS) Systems: For brick-and-mortar stores, POS systems can track in-store purchases. Surveys and Feedback Forms: Customers can also provide information about their past purchases through surveys and feedback forms.