What is Promotional lift?

Promotional lift matters because it tells you how much extra stock you need before running a sale, not just your normal reorder quantity. If you plan inventory using regular sales speed and ignore lift, you sell out mid-promotion and miss the rest of the sales the promotion would have brought in.

To use it, look at past promotions for the same or similar product and compare sale-period sales to normal sales over the same number of days. Apply that lift factor to your current baseline demand to size the order, and place it early enough that the stock arrives before the promotion starts.

Formula

Example

A candle store normally sells 20 units a week. During a 20 percent off promotion last quarter, they sold 50 units in a week. Lift = (50 - 20) / 20 = 1.5, or a 150 percent lift. If they plan a similar promotion this quarter with a normal baseline of 25 units a week, they should plan for around 25 + (25 x 1.5) = 62.5, so order 63 units for the week.

Common mistakes

• Using average daily sales instead of accounting for the promotion when setting reorder quantities.
• Assuming every promotion gets the same lift regardless of discount size or season.
• Forgetting that lift pulls forward future sales, so demand right after the promotion often drops below normal.

Promotional lift and SteadyShelf

SteadyShelf forecasts based on normal sales patterns, so for a planned promotion you still need to manually bump up the suggested order quantity to cover expected lift.

SteadyShelf is launching on the Shopify App Store. Join early access to get the install link first.

Related terms

Demand forecasting · Baseline demand · Seasonality · Demand spike · Sell-through rate

Full inventory glossary

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