This post was triggered by my recent series, The Retail Reset. Details below.
Waiting in a Costco checkout line on a Saturday will do something to you.
Specifically, I started wondering why Costco never seems worried about anything. While everyone else in grocery is panicking about AI and overlooking marketplaces, Costco doesn't lose sleep over either.
Costco solved it decades ago. Not with technology. With a behavioral commitment.
🎫The membership.
Over 82 million households globally hold one. Renewal rates exceed 92% in North America1.
Those numbers sound like retention metrics. They’re actually something more interesting.
A membership is a pre-committed decision to shop.
When someone renews in January, they’ve already decided where a significant chunk of their shopping happens for the rest of the year.
Before any AI assistant surfaces a cheaper option. Before any marketplace search result. Before any price comparison app kicks in. The destination is already set.
Most retailers compete trip by trip. Every basket is a new decision, up for grabs. And that’s exactly what marketplaces are built to exploit. They intercept the moment of choice. They exist at the moment of choice.
Costco just moved that moment earlier.
🔄Instead of competing at checkout, they compete at renewal. That’s a completely different game.
One where the outcome is mostly decided before the customer even thinks about what they need this week.
Once someone has paid for access, the psychology shifts in ways that compound over time. They want to justify the fee. Trips consolidate. Baskets get bigger. The store becomes the default, not a considered option.
Costco doesn’t win the trip. It wins the starting point.
Many mid-tier grocers are trying to win customers within interfaces they don’t own: Instacart, DoorDash, and, soon enough, whatever AI shopping layer gets built on top of them all.
🏦They’re renting visibility on someone else’s platform and hoping their price is good enough that day.
The real question is simpler. Who sets the default shopping behavior?
Whoever sets the default doesn't need to win every basket. They already won the decision that actually matters. Where the customer starts.
The Retail Reset is a 10-part series on why mid-tier grocers are handing customer ownership to platforms, and what they can do to take it back.
The full series:
“Costco’s Membership Model Continues to Deliver Predictable Growth.” Zacks: https://finance.yahoo.com/news/costcos-membership-model-continues-deliver-145900455.html