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, so you can boost products contextually. For example, boost “sale” items only for visitors from a specific campaign.
How soft boost expressions work
When you add an expression in the rule’s Expressions tab, you can choose from four expression types:- Promote: Forces all matching products toward the top of the sort order as a group.
- Demote: Forces all matching products toward the bottom of the sort order.
- Soft Boost: Nudges matching products up within the base sort, interleaving them throughout the results instead of clustering them.
- Product Diversity: Limits how many products from the same group appear near the top. See Diversity expressions.
Boost modes
When you configure a soft boost, you choose one of two modes. New soft boosts start in Lift matches into view. Lift matches into view lifts matching products toward a target value taken from the rest of the catalog, so they move up even when they have zero or near-zero values on the base sort metric. Best for sprinkling in products that may not have metric data yet, like new arrivals, recently restocked items, or products in a new category. Amplify strong performers adds a percentage on top of each matching product’s existing value on the base sort metric. Because the lift is a percentage of the existing value, a match with no metric data (a value of zero) doesn’t move, and matches need real metric data to benefit. The percentage also shrinks as the base value grows, so matches that already score high get a proportionally smaller lift than matches with lower (but non-zero) values. The metric stays the main signal: a weak match won’t leapfrog a much stronger non-match. When the base metric’s values are too large for this shrinking percentage to produce any lift, Layers applies the boost the way Lift matches into view does instead, so the boost still moves matches. See Soft boost for details on the automatic switch.Configuration parameters
Lift matches into view was updated on 2026-08-20 so that the percentile target alone decides where matches land: every matched product lifts the full distance to the target, regardless of any stored boost strength. Existing merchandising rules that use this mode continue to work, but if matches are now landing higher than expected, lower How high should matches land? to restore the previous placement.
When to use soft boost vs. promote
Soft boost expressions live inside a merchandising rule, so they follow the rule’s contextual conditions like any other expression. You can combine contextual conditions (geo, device, customer segment) with soft boosts to target specific audiences.