Your ecommerce cash flow is lying to you — here’s the real number
Revenue is up, margins look healthy, and the bank balance is shrinking. Here’s why growing ecom brands run out of cash — and how to see it coming.
Jakob Sperber
Director
Innovation
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Here’s a scenario that plays out constantly in ecommerce: revenue is growing, margins look solid on paper, the agency is sending reports full of green arrows — and the bank balance is going down.
It’s not fraud. It’s not bad accounting. It’s a cash flow timing problem that’s built into the structure of every DTC business. And most founders don’t see it until it’s already a crisis.
Why profitable businesses run out of cash
The core issue is timing. In ecommerce, cash goes out before it comes back in — and the faster you grow, the wider the gap.
Cash out (immediate):
Ad platforms charge daily. Meta debits your account every day. Google does the same.
Inventory is paid for weeks or months before it sells. A purchase order placed today might not generate revenue for 60–90 days.
3PL and shipping costs are invoiced weekly or monthly.
Cash in (delayed):
Shopify Payments pays out every 2–3 business days (better than most, but still a lag).
Marketplace payouts (Amazon, The Iconic) can take 14–30 days.
Returns and chargebacks claw back revenue 30–90 days after the sale.
The result: on any given day, you’ve already paid for the ads, the stock, and the fulfilment of customers who haven’t paid you yet — or whose payments haven’t cleared. Scale that up, and the gap scales with it.
The cash conversion cycle
The metric that captures this is the cash conversion cycle (CCC): the number of days between paying for inventory and receiving cash from the customer who bought it.
CCC = Days Inventory Outstanding + Days Sales Outstanding − Days Payable Outstanding
Days Inventory Outstanding (DIO): How long inventory sits before it sells. High DIO = cash tied up in stock.
Days Sales Outstanding (DSO): How long after a sale until cash lands in your account. For Shopify direct, this is 2–3 days. For wholesale/marketplace, it’s 14–60 days.
Days Payable Outstanding (DPO): How long you have to pay your suppliers. Longer payment terms reduce CCC.
Example
A brand orders inventory with 30-day payment terms. The inventory takes 45 days to sell on average. Shopify pays out in 3 days.
DIO: 45 days
DSO: 3 days
DPO: 30 days
CCC: 45 + 3 − 30 = 18 days
That’s 18 days where cash is locked up in the business between paying for stock and getting paid by customers. Not terrible. But add ad spend (which has zero payment delay — your credit card is charged immediately) and the effective CCC is much worse.
Where ad spend makes it worse
The cash conversion cycle calculation above doesn’t include marketing spend — and marketing is usually the biggest cash outflow for scaling DTC brands.
If you’re spending $500/day on Meta and $300/day on Google, that’s $5,600/week going out immediately. The revenue from those ads trickles in over 1–7 days (click to purchase isn’t instant, especially for higher-AOV products). Then Shopify holds it for another 2–3 days.
For a brand spending $24,000/month on ads, there’s always $6,000–$8,000 in ad spend that’s been charged but hasn’t been recovered in revenue yet. Scale to $50K/month and that float is $12–$15K. It’s not a loss — but it’s cash you don’t have access to, and it grows every time you increase spend.
The funded growth rate
Your funded growth rate is the maximum rate at which you can grow using only internally generated cash. It’s determined by:
CM3 per customer — how much profit each new customer generates after acquisition cost
CAC payback period — how fast that profit comes back
Cash conversion cycle — how fast cash moves through inventory
If your CM3 is thin, your payback is long, and your CCC is high — you can’t grow very fast without external capital. The business needs to finance the gap between cash out and cash in, and that financing has a cost (interest, equity dilution, or simply not growing).
This is why two brands with identical revenue and identical margins can have completely different growth trajectories. The one with faster payback and shorter CCC can reinvest cash more often. Compound that over 12 months and the difference is enormous.
How to improve your cash position
Compress the cash conversion cycle
Negotiate longer payment terms with suppliers. Moving from 30-day to 60-day terms effectively gives you an interest-free loan.
Reduce inventory days. Better demand forecasting, smaller more frequent orders, or dropshipping for long-tail SKUs.
Speed up payouts. Shopify’s daily payout option. Avoid marketplaces with long settlement cycles for your primary channel.
Improve payback speed
Increase first-order AOV. Bundles, free shipping thresholds, upsells. Higher AOV means more CM2 per order, which means faster payback.
Accelerate repeat purchases. Post-purchase flows, subscription offers, replenishment triggers. Pull the second order forward.
Lower CAC. Better targeting, creative testing, conversion rate optimisation. Less money out the door per customer.
Bridge the gap with financing
Revenue-based financing (Wayflyer, Clearco): borrow against future revenue to fund inventory or ad spend. Good for bridging predictable gaps. Expensive if payback is slow.
Business credit cards: 30–55 day float on ad spend. Effectively extends your DPO on marketing costs.
Inventory financing: Fund purchase orders against confirmed demand. Useful for seasonal stock builds.
Building a cash flow forecast
A P&L tells you if you’re profitable. A cash flow forecast tells you if you can afford to be profitable next month. They’re different documents that answer different questions.
Your cash flow forecast should map:
Committed cash out: Upcoming inventory POs, ad spend at current run rate, fixed costs, loan repayments
Expected cash in: Revenue at current run rate, payout schedules, pending marketplace settlements
The gap: Where cash in doesn’t cover cash out, and how long the shortfall lasts
Update it weekly. If the gap is widening, you need to either slow growth, improve margins, or arrange financing before you hit the wall.
The bottom line
Revenue and profit are accounting concepts. Cash is what’s actually in the bank. A business that’s profitable on paper but cash-negative in practice will eventually stop operating — no matter what the P&L says.
Map your cash conversion cycle. Know your funded growth rate. And build your growth plan around the cash you actually have, not the revenue you’re projecting.
