Why merchandising rules exist

Algorithmic recommendations optimise for a metric, usually conversion or revenue. But a business
has goals the metric cannot see: launching a new arrival, pulling a defective item, promoting a
partner’s exclusive collection.

Merchandising rules are the control surface between business logic and the algorithm. They let
category managers and marketers govern the output without code.

The main rule types

Rule type Action Example
Boost Lift in the ranking New arrivals always in the top three
Bury Push down Items rated below 3.5 go to the end
Pin Fix a position The deal of the day is always first
Exclude Remove Drop out-of-stock items and items with no photo
Include Force in A promotional item is always shown

How rules interact with the algorithm

The typical architecture: the algorithm generates a ranked candidate list → the rules adjust the
order or the composition → the final output reaches the shopper.

Algorithm: [A, B, C, D, E, F...]
Rule: pin item X to position 1
Rule: exclude out-of-stock (removes C)
Result: [X, A, B, D, E, F...]

Important: the more hard rules there are, the less room personalization has. If the first five
positions are pinned, the algorithm only influences what is left.

When to use them and when to hold back

Rules are justified for:

  • Promotions with fixed positions (Black Friday, a collection launch)
  • Technical constraints (removing items with no photo or no price)
  • Partner commitments (a guaranteed share of impressions for a brand)

Rules create risk when:

  • There are too many of them and they conflict with each other
  • They are permanent rather than time-bound, blocking the algorithm from adapting
  • No A/B test confirms the business effect