A proof-of-purchase collector is an individual who actively seeks and accumulates physical evidence of their purchases, such as receipts, barcodes, or packaging, as a way to track and validate their consumer activity. This practice is often motivated by a desire to redeem rewards, participate in loyalty programs, or simply keep a record of their spending habits. The proof-of-purchase collector takes pride in their collection and may view it as a form of personal achievement or a way to showcase their brand loyalty.