Methods, apparatus, systems and articles of manufacture to identify media sources are disclosed. Example apparatus disclosed herein include an exclusivity determiner, a unique asset identifier, and a signature matcher. The exclusivity determiner is to determine whether media is exclusive to a provider. The unique asset identifier is to associate a first signature of the media with the provider if the media is exclusive to the provider. The signature matcher is to identify the provider based on a second signature, the second signature matching the first signature, the second signature extracted from media presented at a media presentation location.