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Comment by bell-cot | Hacker News Reader

Costco's position seems pretty unremarkable to me. What % of modern retail sales are both paid in cash, and unconnected to any loyalty/reward program? I'd bet it's under 10%. And even then, a company could refund everyone it knew about, then say "bring in your receipts" for the remainder.

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Costco requires a membership, and they do store credit back at higher tiers. They absolutely know what every member buys.

My point was that the other stores do, too. Or 90-ish %.

I remember a story on Walmart's data analysis capacity being something like 2 years of line item data for a customer. I've read numbers that suggest 10PB / day ingested from their ecommerce operations and 2-3 PB/hr data processing. Pretty incredible.

For modern ecommerce, figurative recording every twitch of your mouse in their store, I'd believe that.

But to save only the "SKU, qty., unit price, date" receipt info - which you would need to process tariff refunds - that'd be maybe 16 bytes per receipt line? To hit even 1TB/day, you'd need a billion customers, each buying 64 items. On that one day.

I suspect they're looking at the cost of implementing a one time refund/credit vs. reducing prices without the need to implement anything special.

Yes, I'm being charitable but not having to spend part of the refund on an extra program could benefit their customers more in the long run.

(We're Costco members.)

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