A unified system of unique identifiers is used to match enrichment content with primary content being delivered by subscribers, e.g. broadcasters, in different markets, market segments, etc. Songs, video, advertisements, or other content from multiple different content publishers or databases, each of which may be assigned identifiers using different identification systems, are assigned a unified, unique identifier. The unique identifiers are also mapped to content identifiers used by subscribers. When subscribers provide primary content, for example by broadcasting the content to end users, enrichment content is matched to the unified, unique identifier associated with the content, and appropriate enrichment data and content are sent to the subscriber for distribution along with the primary content.