What is pull-forward effect and why does it matter?

Pull-forward is when customers buy during a sale who would have bought anyway at full price, just later. A 30% off sale might generate $100K in revenue, but if $40K of that would have happened next week anyway, the truly incremental revenue is only $60K. Meanwhile, you lost the full margin on that $40K. The calculator starts from our assumed pull-forward share for your category, which you can replace with your own figure, or measures it directly when you connect Shopify.

How is true promo profit calculated?

True promo profit is the margin earned on incremental orders at the discounted price, minus the margin given up on orders that would have happened anyway (pulled forward or cannibalised), minus an allowance for teaching buyers to wait for the next sale (a fixed share of promo revenue, which is our assumption). It does not subtract ad spend: the tool does not ask for it. Most brands look only at top-line revenue lift, ignoring that part of that lift was pulled from sales they would have made later at full price.

What is margin erosion?

Margin erosion is the profit you lose by discounting. On a product with 60% margin, a 30% discount does not just reduce margin to 30%, it is worse. If COGS is $40 on a $100 product, selling at $70 means margin drops from $60 to $30 (a 50% reduction in profit per unit). The tool prices this hit on every discounted order.

Are Black Friday / BFCM sales profitable?

Often less than brands assume. We assume 30 to 50 percent of BFCM purchases are pull-forward from customers who would have bought in December anyway. This is our assumption, not an industry figure and not measured from your account. Heavy discounting combined with elevated CPMs can compress real profit.

Which promotions are typically most profitable?

Our view, not a measurement: Gift with Purchase and tiered discounts often do better than site-wide percent-off, because they raise AOV without training every customer to expect a discount. Free shipping at threshold can protect margin. Site-wide percent-off is often the weakest because it discounts customers who would have paid full price.

Can I run this on real Shopify data?

Yes. Connect Shopify and the tool pulls your discount codes, baseline daily orders, and post-promo windows to measure pull-forward from your actual data instead of estimating it from category benchmarks.

Your catalogue, open to AI shoppers.

See how

See your true promo P&L after pull-forward and margin loss.

Enter your promo inputs or connect Shopify for real order data. Decomposes lift into incremental vs. pull-forward, computes the gross-margin hit on discounted units, and surfaces a net profit verdict.

FelixForecasting

Promo name *

Promo type *

Discount % *

Promo results

Orders *

Duration (days)

Baseline metrics

Normal AOV *

Currency

Gross margin % *

Normal orders per day

Industry (optional)

Our assumptions

These two figures decide the split between orders you would have won anyway and orders the promo created: whatever they leave is counted as new. The net profit moves with them. They are our starting assumptions, not measured from your store. Change either if you know better.

Pull-forward %

Cannibalisation %

Pull-forward and cannibalisation are shares of the same orders, so together they cannot be more than 100%.

Revenue is counted at the price paid (AOV minus the discount). The promo's orders are split three ways: orders you would have had anyway (your normal daily orders times the duration, when you give it), orders pulled forward from later weeks, and new demand. Net profit = margin on new demand, minus the margin given away on orders you would have had anyway, minus the full margin lost on pulled-forward orders, minus a 2% of revenue charge for customers learning to wait for a discount, minus the margin on any orders below your normal level. Pull-forward and cannibalisation start from our per-category assumptions, shown on the form and editable.

A promo's P&L depends on the store running it. The full growth audit runs seven checks against your live site, including the catalogue and landing page the discount drives traffic to, plus the tracking that will price the result.

Run the free growth audit