Industries consulting
Ecommerce growth: contribution margin, order value and repeat rate
Ecommerce growth consulting means increasing profit rather than sessions — which in practice means understanding your contribution margin, raising average order value, and improving the share of first-time buyers who come back.
Why is contribution margin the first number?
Revenue minus cost of goods, shipping, payment fees, packaging and returns is what a customer is actually worth. Every marketing decision — the maximum you can bid, whether a discount is worth offering, whether paid acquisition works at all — depends on this number, and a surprising number of retailers cannot state it.
Calculate it per order and per customer, then work out how many orders a typical customer places in their lifetime. Those two figures together give you the ceiling on what you can afford to acquire a customer for, which is the number every channel decision should be measured against.
Which levers raise average order value?
Four levers, roughly in order of reliability. Bundling and volume pricing works well and rarely annoys anyone. Free shipping thresholds work well because they convert an otherwise unwilling purchase rather than penalising one. Post-add-to-cart cross-sell works when genuinely relevant and becomes irritating when it is not. And discounting is the most reliable and the most costly — it works by conditioning customers to wait for offers.
| Lever | Typical effect | Risk | Implementation |
|---|---|---|---|
| Bundling | Moderate AOV lift | Cannibalises full-price single purchases if poorly designed | Bundle on complementary items, not unrelated ones |
| Free shipping threshold | Strong, clean lift | Margin cost if threshold set too low; logistics cost applies to all units | Set just above your current average order value |
| Post-add-to-cart cross-sell | Moderate, high margin | Cart abandonment if overdone | One or two genuinely relevant items only |
| Tiered volume discount | Good for high-AOV categories | Trains customers to buy more than they need | Use where product is durable or consumable |
| Discounting | Highest immediate volume | Conditions customers to wait; erodes perceived value | Rarely, time-limited, and on full-price items |
Why is repeat rate the cheapest growth available?
Acquiring a new customer costs whatever the channel charges. Retaining one costs a fraction of it, and the second purchase is more profitable than the first because there is no acquisition cost, no shipping subsidy and often a higher order value as the customer discovers more of the catalog.
Ninety-day repeat rate is therefore the closest single proxy for whether an ecommerce business is fundamentally working, and it is usually a better predictor of profitability than traffic or conversion rate. A store converting at 2% with a 25% ninety-day repeat rate can be in better shape than one converting at 4% with a 6% repeat rate.
- Establish the baseline: what is your ninety-day repeat rate, and how does it vary by acquisition channel and first-order category?
- Build the four core flows — welcome, abandoned cart, post-purchase, win-back. None require new technology.
- Fix email authentication before scaling any volume. Deliverability failures here are silent and expensive.
- Segment by purchase behavior. Vague and repeat categories respond to completely different messages and offers.
- Target the second order specifically. A first-order discount of 15% is a weaker driver of a repeat purchase than a modest second-order incentive.
How do you choose between paid social and SEO?
Decide by margin and by how quickly you need revenue, not by which channel is trending. Paid social buys volume now and stops the moment you stop paying. SEO compounds but takes four to nine months to produce meaningful revenue and requires content volume you may not have.
| Business situation | Lean toward | Because |
|---|---|---|
| Thin margin, need revenue this quarter | SEO and retention | Paid acquisition at thin margin rarely works; retention is free |
| Healthy margin, need volume now | Paid social | Buys immediate revenue while SEO builds |
| No content capacity, urgent need | Paid social | SEO requires sustained publishing you cannot currently do |
| Strong content capacity, patient | SEO | Compounding returns over 6–12 months |
| Repeat purchase is common | Email and SMS first | The cheapest revenue available; usually before either |
| Highly seasonal | Both, weighted to paid pre-peak | Organic builds too slowly for a seasonal window |
How should you plan around seasonality?
Seasonality is a cash-flow problem before it is a marketing problem, and it needs planning on a longer lead time than most retailers assume. Organic and content work requires four to nine months to pay off, so a peak season requires starting roughly two quarters ahead — which means deciding in the spring for a Christmas peak.
The practical structure: identify your peak and shoulder periods from historical data rather than assumption, then work backwards. Content and SEO need the longest lead. Paid media needs four to eight weeks of testing before it is efficient. Email to your existing list can be deployed in days. Inventory and operational capacity need to be decided before the demand arrives, not during it.
When is more traffic the wrong decision?
When the bucket leaks. If conversion rate is weak, average order value is low and repeat rate is poor, additional traffic simply increases the cost of the same problem. This is the most common expensive mistake in ecommerce, and it is usually made because traffic growth is the easiest number to report upward.
The honest diagnostic is short: what is your contribution margin per order, and what percentage of first-time buyers return within ninety days? If both numbers are weak, more traffic makes things worse. Fixing conversion and retention first is almost always the higher-return path.
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Frequently asked questions
What is contribution margin and why does it matter for ecommerce?
Revenue minus cost of goods, shipping, payment fees, packaging and returns. It determines the maximum you can afford to pay to acquire a customer, so every marketing decision depends on it. Returns must be included — a category with a 12% return rate has materially different economics from one at 4%, and a return often consumes the original profit twice.
What is a good ecommerce conversion rate?
There is no useful universal figure, because it varies enormously by category, price point, traffic source and device. A published average mixes cold and warm traffic and will mislead you. The more useful comparisons are against your own previous performance and against the segment of your traffic that actually buys. Indicative ranges exist in the benchmark guide, with the caveats they require.
Is 90-day repeat rate a good primary metric for ecommerce?
Yes, and it is usually a better predictor of profitability than conversion rate or traffic, because it captures whether the business works after the first transaction. A store converting at 2% with a 25% ninety-day repeat rate is frequently in better shape than one converting at 4% with a 6% repeat rate, since the second purchase carries no acquisition cost.
Should we increase average order value or conversion rate?
Usually AOV first, because AOV increases do not cost you traffic. Bundling, free shipping thresholds and relevant cross-sells raise AOV without adding friction. Conversion improvements require changing the page a visitor already chose not to convert on, which is harder and less certain. Watch both together — AOV rising while conversion falls is not a win.
How much of our budget should go to paid social versus SEO?
Decide by margin and patience rather than trend. Paid social buys immediate revenue and stops the moment you stop paying; SEO compounds over four to nine months and needs sustained content capacity. If margin is thin, paid acquisition frequently does not work at all and retention should be funded first. Both are usually worse investments than fixing email and lifecycle flows.
How early should we plan for peak season?
Roughly two quarters ahead for a content and SEO-driven peak, since organic work needs four to nine months to produce meaningful revenue. Paid media needs four to eight weeks of testing before it is efficient. Email to an existing list can deploy in days. Inventory and operational capacity need to be committed before demand arrives, which is the constraint most retailers discover too late.
Should we sell through marketplaces as well as our own site?
Marketplaces offer reach and trust a new brand has not yet earned, and they constrain your customer relationship, your margin and your data access. A sensible pattern is to use them for discovery and push customers to your own site where the economics allow, subject to marketplace terms — which vary on this and are often restrictive. Decide deliberately rather than by default.
Our acquisition costs keep rising as we scale. Is that normal?
Partly. Rising costs as you saturate an audience are normal and worth monitoring. Rising costs caused by your own campaigns competing with each other, or by progressively broader targeting to extract volume from a saturated audience, is structural. The diagnostic: if cost per acquisition rises faster than conversion rate improves, you are buying less with each additional unit of spend.
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