Costco’s digital playbook is quietly becoming one of retail’s most disruptive growth engines.
Digital sales are Costco’s stealth growth engine—and it’s working.
While everyone fixates on Amazon’s next drone drop or Walmart’s AI-powered grocery app, Costco is quietly stacking wins in the ecommerce game—and it’s starting to matter.
Costco’s ecommerce growth isn’t slowing down
In fiscal Q3 2025, Costco’s ecommerce sales jumped 14.8% year-over-year. That’s nearly double its overall sales growth of +8%—and the sixth consecutive quarter of double-digit digital gains.
Even more telling? Ecommerce comparable sales—excluding gas and currency noise—spiked 15.7%, with site traffic up 20% and average order value climbing 3%.
This isn’t a sideshow anymore. Costco’s digital playbook is becoming a core growth lever.
The catch: ecommerce is still just 8% of total sales
Here’s the twist—the digital channel still makes up roughly 8% of Costco’s $85.9 billion quarterly sales. But that’s exactly what makes this story spicy.
Costco is turning ecommerce into a high-margin, operationally integrated growth engine, without trashing the bulk-buy, warehouse-club DNA that built its empire.
What’s fueling digital momentum?
- BNPL rollout: Costco launched Buy Now, Pay Later with Affirm for online purchases. Big win for appliances, tech, and high-ticket items.
- Personalized product recs: Smart, obvious, member-based suggestions—not creepy AI vaporware.
- Targeted campaigns: Mother’s Day promos based on past purchases boosted digital spend.
- Logistics investments: Bulky-item deliveries surged 31%, thanks to Costco Logistics.
- Category expansion: Digital sales spiked in apparel, jewelry, health & beauty, toys, and home goods.
- Third-party marketplace pop: Costco Next online marketplace matched FY22’s total sales—just in Q3.
Costco vs. Amazon and Walmart: Different plays, same battlefield
Amazon’s still the king of speed, with Prime Now redefining delivery expectations. Walmart’s ecommerce sales soared 22% last quarter, fueled by fulfillment scale and marketplace expansion.
But Costco isn’t chasing that chaos.
Instead, it’s building a hybrid model:
- 79.6 million paid members fueling recurring revenue
- $1.24 billion in quarterly membership income
- 11.25% gross margin, ticking upward
- 92.7% U.S. and Canada renewal rates
The ecommerce layer? It reduces churn, boosts order value, and locks in retention—without eroding Costco’s operational edge.
The operator POV: what founders can steal from this
- Membership + ecommerce = cash printer. Recurring revenue buys pricing power most can’t touch.
- Personalization doesn’t have to be creepy. Use real buyer behavior, skip the AI buzzwords.
- Big-ticket logistics pay off. More deliveries, higher AOV, better CLTV.
- You don’t have to “win” online. You just need to own your customer’s digital journey.
Why this matters now
Costco stock’s up 15.5% over the past year, crushing the retail sector’s weak 5.6% climb. But its valuation’s frothy—P/E ratio at 50.11 vs. industry average 32.13.
Translation? Investors are betting big on Costco’s hybrid strength.
So what?
Costco’s ecommerce game isn’t a tech hype cycle—it’s a business fundamentals flex. The bulk retailer is building a defensible moat most competitors can’t copy:
Warehouse scale + Membership loyalty + Targeted digital = Durable growth.
And in a retail world littered with layoffs, crime waves, and bankruptcies? That quiet, boring model is exactly what wins.
