This is the second post of a 10-part series: The Marketplace Trap. If you are starting here, it’s best to read the first post for context.
Online grocery is growing. That’s not the debate.
The real question is quieter: who owns the customer when that growth happens?
Two identical households can generate very different lifetime value depending on one variable. Did they order through the grocer’s owned app and loyalty ecosystem, or through a marketplace?
And here’s what most organizations aren’t asking: is digital growth strengthening profitability, or transferring it to third parties?
Digital penetration has become the headline KPI. Ten percent. Fifteen percent. Twenty percent growth in online sales. Grocers celebrate the number. Boards nod. Investors reward it.
But the metric is incomplete.
It tells you how much is being sold online. It says nothing about who owns the relationship behind that sale or the profitability that comes with it.
When high-value omnichannel households shift toward third-party platforms, the economics reorganize. Search happens on someone else’s property. Loyalty accrues in someone else’s app. Retail media that should flow back to the grocer gets split. And the behavioral data that fuels personalization? It weakens.
Sales go up. Ownership goes down. Those are two very different scoreboards.
Let’s look at the math.
Start with a Normal Household
A strong omnichannel grocery household can generate roughly $62,000 in revenue over five years1. About 17% of that flows through eCommerce2.
Zoom in on the digital portion. That’s $2,108 per year. Let’s assume that’s 2 orders per month with a 26% gross margin3 and $10 per-order fulfillment cost4.
Gross profit:
$2,108 × 25% = $548
Fulfillment:
24 × $10 = $240
Annual contribution:
$548 – $240 = $308
Same shopper. Same basket. Same cost structure. That $308 is the starting point in both scenarios.
Grocer-Owned Economics
When the grocer owns the digital relationship, small advantages compound. Loyalty data sharpens targeting. Better substitution improves retention. App engagement reinforces habit. Retail media economics stay in-house.
Conservatively, that’s worth $52 per year in incremental value.
Owned annual value:
$308 + $52 = $360
Over five years:
$360 × 5 = $1,800
That’s the five-year profit contribution from the digital portion of one household when the grocer owns the relationship.
Marketplace Economics
Now, assume those same orders flow through a marketplace.
Transaction fees typically range from 6-7% of gross transaction value5. Let’s use 7%.
Marketplace fee:
$2,108 × 7% = $148
Ownership compounding weakens. Subtract the same $52.
Marketplace annual value:
$360 – $148 – $52 = $160
Over five years:
$160 × 5 = $800
The Delta
Five-year profit contribution:
Grocer owned: $1,800
Marketplace routed: $800
Difference: $1,000
Over that same five-year period, roughly $740 in transaction fees alone are transferred to the platform.
Effective contribution margin drops from roughly 17% to 8%.
That’s not a rounding error.
Across hundreds of thousands of customers, that compounds into tens of millions shifted away from the grocer.
What This Actually Means
Marketplaces aren’t the enemy. They find new customers, extend reach, and fill capacity. Used strategically, they can expand the top of the funnel.
But they also accumulate control. When they own discovery and sponsored placement, they’re not just moving orders. They’re capturing the most profitable layer of the stack.
A grocer can win the quarter while losing in the long term.
The more useful questions are:
How many online customers do you actually know?
Are owned customers worth more than marketplace customers over time?
Are you building an asset, or renting one?
Growth measures velocity.
Ownership measures profitability.
And once ownership shifts, it’s difficult to reclaim.
That’s the $1,000 problem in grocery eCommerce.
The Marketplace Trap 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:
Estimate based on an average annual household spend of $12,408 per year. “State of the Industry: The Omnichannel Grocery Shopper.” Grocery Doppio: https://www.grocerydoppio.com/research-report/the-omnichannel-grocery-shopper
“Grocery e-commerce hits record high household penetration.” Grocery Drive: https://www.grocerydive.com/news/grocery-ecommerce-online-sales-july-household-penetration/757641
“Margins by Sector.” NYU Stern School of Business: https://pages.stern.nyu.edu/~adamodar/New_Home_Page/datafile/margin.html
“Online Grocery Order Fulfillment Cost Comparison.” MWPVL International: https://www.mwpvl.com/html/online_grocery_order_fulfillment_cost_comparison.html
“Instacart Form S-1 Registration Statement, 2023." U.S. Securities and Exchange Commission: https://www.sec.gov/Archives/edgar/data/1579091/000119312523231909/d55348ds1a.htm