Costco’s ecommerce sales are growing fast — but instead of chasing Amazon, it’s building a hybrid model rooted in operational muscle and member loyalty.
Digital sales are quietly becoming Costco’s most important growth engine — and a competitive moat most retailers can’t replicate.
Costco ecommerce sales rise 14.8% in Q3 and it’s not a fluke
Forget the “Costco is just a warehouse club” narrative.
For the sixth straight quarter, Costco’s ecommerce business grew by double digits — clocking in at +14.8% YoY in fiscal Q3 2025. That’s nearly double the company’s overall +8% net sales growth, and even outpaces its healthy +13.2% jump in net income for the quarter.
This isn’t just another line item. It’s a tectonic shift.
The catch: ecommerce is still just 8% of sales
Despite the surge, ecommerce only makes up ~8% of Costco’s total sales.
But that’s exactly what makes this story so interesting.
Because the biggest player in bulk brick-and-mortar retail is turning ecommerce into a profitable, operationally integrated growth lever — without sacrificing the high-volume, low-margin DNA that made it a $60B+ quarterly behemoth.
What’s driving digital growth?
🛒 BNPL rollout: In Q3, Costco quietly launched Buy Now, Pay Later with Affirm. That’s huge for discretionary and high-ticket digital buys.
🎯 Personalized product recs: They debuted a recommendation hub that serves members items based on browsing history, region, and past purchases.
🎁 Targeted campaigns: A Mother’s Day campaign hit members who bought gifts in 2024. It worked.
📦 Logistics investments: Deliveries of big and bulky items jumped +31%, thanks to Costco Logistics.
🛍️ Category winners: Ecommerce sales popped in apparel, jewelry, health & beauty, toys, and home goods — areas where digital makes the experience better (and where margins are fatter).
🧰 Costco Next: Their third-party online marketplace had a breakout quarter — Q3 sales matched all of FY22.
Why it matters: Costco’s ecommerce isn’t Amazon — and that’s a good thing
Amazon built a digital empire on endless choice and Prime. Costco’s ecommerce play is lower volume, higher intent — and tied to a subscription flywheel.
📈 79.6M paid members
💰 $1.24B in Q3 membership income
📉 11.25% gross margin — up YoY
🔁 92.7% renewal rate in U.S. and Canada
Costco doesn’t need ecommerce to lead. It just needs it to reduce churn, increase order value, and improve retention. So far, it’s working — and it’s wildly profitable.
Operator POV: Here’s what founders should take from this
- Subscription + ecommerce = cash printer. Costco’s recurring revenue gives it margin flexibility most retailers dream of. If you can pull off membership, even at a smaller scale, you unlock pricing leverage.
- Personalization doesn’t require creepy data scraping. Costco’s product recs are simple, obvious, and based on real member behavior. Smart segmentation > AI vaporware.
- Logistics scale matters. Costco’s investment in delivery (and haul-away) of big, high-margin items isn’t just customer service — it’s AOV and CLTV expansion.
- You don’t need to win online. You need to win your customer online. Costco isn’t trying to be everywhere. They’re trying to own the customer journey for their 142.8M cardholders.
So what?
While everyone else is busy yelling about retail apocalypse, Costco is quietly building a hybrid moat:
📦 Warehouse scale + 💳 Subscription stickiness + 🛍️ Targeted ecommerce = durable growth.
And here’s the kicker: most retailers can’t copy this playbook.
Costco’s ecommerce strategy only works because of its unique membership model, supply chain control, and cultural obsession with operational excellence.
It’s not a tech story. It’s a business fundamentals story. And that’s exactly why it’s working.
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