Providing enrichment content

A processing system comprising:

• a processor and associated memory configured to:
• assign different unique identifiers to each of a plurality of different instances of a content item, wherein the different unique identifiers have values included in different ranges of unique identifier values;
• store first information linking particular subscriber identifiers used by particular subscribers to refer to particular instances of the content items;
• store second information associating an enrichment identifier with a collection of enrichment content;
• store third information associating the enrichment identifier with a particular range of unique identifier values;
• and
• deliver enhanced content to subscribers based on the first information, the second information, and the third information.

A non-transitory computer readable medium tangibly embodying a program of instructions configured to be stored in a memory and executed by a processor implementing a first advertisement management system, the program of instructions including:

• at least one instruction to assign different unique identifiers to each of a plurality of different instances of a content item, wherein the different unique identifiers have values included in different ranges of unique identifier values;
• at least one instruction to store first information linking particular subscriber identifiers used by particular subscribers to refer to particular instances of the content items;
• at least one instruction to store second information associating an enrichment identifier with a collection of enrichment content;
• at least one instruction to store third information associating the enrichment identifier with a particular range of unique identifier values;
• and
• at least one instruction to deliver enhanced content to subscribers based on the first information, the second information, and the third information.