Soft boost in merchandising works the same way as Soft Boost in Sort Orders, but is scoped to a specific merchandising rule instead of applying globally. This lets you boost products contextually — for example, boosting “sale” items only for visitors from a specific campaign.
How soft boost expressions work
When you create an expression in the merchandising rule builder, you can choose between two expression types:- Priority Rule (default): Pushes all matching products to the top of the sort order as a group.
- Soft Boost: Applies a decaying boost that naturally interleaves matching products throughout the results based on their existing sort performance.
Boost modes
Soft boost expressions support two modes: Multiplicative (default) amplifies products that already perform well on the base sort metric. The existing sort value is scaled by a boost factor, so products with higher base values receive a proportionally stronger lift. Best for promoting products that are already performing and have non-zero metric values. Additive (percentile-based) assigns a fixed position based on a configurable percentile target, boosting products even when they have zero or near-zero base values. Best for sprinkling in products that may not have metric data yet — like new arrivals, recently restocked items, or products in a new category.Configuration parameters
| Parameter | Mode | Description |
|---|---|---|
| Boost Strength | Multiplicative | Controls how much the base metric value is amplified (0–2). Higher values push matching products further up relative to their existing performance. Default: 0.25. |
| Percentile Target | Additive | Where matching products land in the sort order (0–100%). At 100% they appear near the top; at 50% they blend into the middle. Default: 50%. |
| Decay Rate | Both | Controls how quickly the boost fades across ranked products (1–500). Lower values concentrate the lift on top matches; higher values spread it more evenly. Default: 100. |
When to use soft boost vs. priority rules
| Scenario | Recommended Type |
|---|---|
| Feature a seasonal tag across the entire collection | Priority Rule |
| Gently promote new arrivals without displacing best sellers | Soft Boost (Additive) |
| Amplify high-performing sale items during a campaign | Soft Boost (Multiplicative) |
| Group products by category or brand at the top | Priority Rule |
| Sprinkle restocked items throughout a best-selling sort | Soft Boost (Additive) |
Soft boost expressions support the same targeting conditions as priority rule expressions. You can combine contextual conditions (geo, device, customer segment) with soft boosts for precise audience targeting.