1. A non-transitory computer-readable medium embodying a program executable in at least one computing device wherein when executed the program causes the at least one computing device to at least: generate a set of product search results by executing a search in a product database in response to receiving a search query from a client; select a subset of a plurality of supplemental content providers based at least in part on respective relevancies of the plurality of supplemental content providers to the search query and a compatibility rule provided by the program that defines compatibility between supplemental content from a first supplemental content provider and supplemental content from a second supplemental content provider as permission to be rendered together in a search results page; receive respective ranked sets of supplemental content from individual ones of the subset of the plurality of supplemental content providers, the respective ranked sets being ranked based at least in part on respective relevance algorithms using the search query; select a subset of a plurality of supplemental content from the respective ranked sets of supplemental content based at least in part on another relevance algorithm that employs at least respective relevancies of the plurality of supplemental content from the respective ranked sets of supplemental content to the search query, wherein the another relevance algorithm employs at least an immediate monetary value and a downstream business value to determine relevance; and generate the search results page that includes the set of product search results and the subset of the plurality of supplemental content, wherein a layout of the subset of the plurality of supplemental content within the search results page is based at least in part on the another relevance algorithm.