Offer Priority & Stacking

How Offer Evaluation Works

Atom Commerce evaluates offers in a specific order to ensure predictable, profitable outcomes. Understanding this system helps you design promotions that work exactly as intended.

Evaluation Order

Priority Within Each Class

Within each offer class, higher-priority offers evaluate first. This ensures the most important promotions take precedence.

Key Rules

• One item-level discount per product line: Only the highest-priority item discount applies
• Order-level evaluates on post-item subtotal: After item discounts are applied
• Shipping-level evaluates last: After both item and order discounts

Stacking Rules

Stacking determines which offer classes can combine together. This prevents margin erosion while allowing strategic combinations.

Common Stacking Patterns

Example Scenarios

Scenario 1: Volume + Order Threshold

Setup: 10% off collection A (item-level, priority 90) + 10% off orders $140+ (order-level, priority 80)

Cart: $150 in collection A products

Result: Item discount fires first → subtotal becomes $135 → order-level no longer qualifies

Scenario 2: Clean Stacking

Setup: 15% off collection A (item-level, priority 90) + Free shipping $75+ (shipping-level, priority 80)

Cart: $100 in collection A products + $10 shipping

Result: Item discount → $85 subtotal → Free shipping applies → Final total: $85

Best Practices

• Set clear priorities: Use distinct priority numbers (90, 80, 70) to avoid conflicts
• Test boundary cases: Try carts just below and above thresholds
• Use combinations intentionally: Allow stacking only where it adds value
• Document your rules: Keep a simple table of active offers and their settings
• Set end dates: Prevent legacy promotions from interfering with new campaigns