This article's domain (Ramp) is a SaaS company that tracks employee expenses for other companies.
Tracking employee credit-cards and reimbursements is part of their service that companies use:
https://ramp.com/expense-management
https://ramp.com/corporate-cards
you can literally buy purchase data from Mastercard, AMEX, and Discover and use this data for retargeting and advanced targeting w ads and run them on Facebook and other platforms.
A dog food purchase? Owner likely has pets, serve em a pet ad, etc.