Similar to another best practice, this guideline aims to avoid confusion when distinguishing site elements.

When a site promotion is displayed directly above a product listing, there is a chance that users will mistake the promotion as part of the product listing.

For example, if a ‘Select sweaters 20% off’ promotion is placed above the product list for all sweaters, site visitors might mistake this product list as being the ‘select’ sweaters that are on sale.

It all depends on how the elements are designed. Displaying a promotion above a product list is acceptable as long as the two elements are clearly distinguishable. Use borders or other visual cues that say these two things are not related.