1. A computer-implemented method comprising: processing a search query by selecting a plurality of item listings that are determined to satisfy the search query; determining an initial ranking score for each item listing in the plurality of item listings; determining, using a computer processor, that a conditional statement of a business rule is satisfied for a first item listing, wherein the conditional statement provides that the conditional statement is satisfied if a shipping fee specified by the first item listing is less than or equal to a median or a mode of shipping fees for a set of item listings offering items determined to be similar to a first item being offered by the first item listing, wherein determining that the conditional statement of the business rule is satisfied includes calculating the mode or the median of the shipping fees; responsive to determining that the conditional statement of the business rule is satisfied for the first item listing, adjusting an initial ranking score for the first item listing with an adjustment factor included in the business rule to generate an adjusted ranking score for the first item listing; presenting a set of the plurality of item listings in a search results page with the first item listing positioned relative to other item listings in the set based, at least in part, on the adjusted ranking score for the first item listing and an initial ranking score or an adjusted ranking score for each of the other item listings.