10. A non-transitory computer-readable medium embodying program code executable by a processing device, the non-transitory computer-readable medium comprising: program code for identifying at least one keyword, wherein identifying the at least one keyword comprises selecting the at least one keyword from a plurality of search terms, wherein each of the plurality of search terms is associated with a respective bid amount; program code for identifying at least one bid amount associated with the at least one keyword; program code for identifying directly relevant content on at least one social media platform, wherein the directly relevant content is identified based on including at least one post that includes the at least one keyword; program code for identifying relevant downstream content on the at least one social media platform, wherein the relevant downstream content includes at least one additional post that is associated with the at least one post and that does not include the at least one keyword and that is relevant to the at least one keyword; program code for generating at least one respective value for at least one metric describing a relevance for the at least one keyword, wherein the value for the at least one metric is generated based on the directly relevant content and on the relevant downstream content; and program code for automatically modifying the at least one bid amount based on determining the at least one respective value for the at least one metric describing the relevance for the at least one keyword.
11. The non-transitory computer-readable medium of claim 10 , wherein the program code for identifying the at least one additional post that is relevant to the at least one keyword comprises: program code for identifying a plurality of posts associated with the at least one post and lacking the at least one keyword; and program code for excluding at least some posts of the plurality of posts by applying a filtering condition indicative of non-relevant content, wherein the at least one additional post satisfies the filtering condition and the at least some posts do not satisfy the filtering condition.