E-commerce promo codes: mechanics, compliance and real impact

Promo codes are the most distributed and least audited marketing tool in e-commerce. An email campaign with a -20% code can be profitable or ruinous depending on the configuration — and the difference is often in 3 checkboxes in the admin that nobody verified.

The 3 types of promo codes and their margin impact

Stacking rules: what many forget to configure

Since 2022, Shopify lets you configure discount combinations. Without explicit configuration, Shopify applies a single discount (the most advantageous for the customer). With stacking enabled, combinations can be dangerous:

• Promo code -20% plus quantity discount -15% plus partner code -10% equals -45% real
• If your gross margin is 40%, you are at negative margin

Basic rule: never stack more than 2 discounts, and always calculate the impact on your low-margin products before launching a campaign.

Promo codes and strikethrough prices: the winning combination

The strategy that converts best combines a visible strikethrough price on the listing (for the visual urgency effect) and an additional promo code for loyal or newsletter subscribers. Example:

• Strikethrough on the listing: -15% (Omnibus-compliant)
• Newsletter promo code: -10% additional, non-stackable with other codes
• Result: loyal customers get -25% total, new visitors see -15% and an attractive strikethrough

Measuring the real impact of a promo code

Three metrics to track after every promo code campaign:

1. Redemption rate (% of recipients who used the code)
2. Average gross margin on orders with promo code vs without promo code
3. Repurchase rate within 90 days (did the code attract loyal customers or one-time deal hunters?)

Seegea's role in the promotional ecosystem

Seegea does not manage checkout promo codes directly — that is the role of Shopify or PrestaShop. However, Seegea manages the catalog side: the strikethrough prices that accompany campaigns (bulk setup, Omnibus compliance, return to full price at end date).

When a promo code campaign ends, Seegea cancels the associated strikethrough prices in 2 minutes across the entire catalog — no missed products, no manual intervention.