Advertising audience monitoring in a content distribution system

A system for monitoring an audience of an advertisement over a content distribution system, wherein the advertisement comprises an advertising message associated with digital audio content distributed to a user of the content distribution system, the system comprising a first user device, a second user device connected to the first user device and a data collection server being configured to communicate with the second user device over a data communication network, the first user device being configured to:

• receive the digital audio content;
• and
• play the digital audio content with the advertising message,
• extract an advertising identifier from the advertising message, and
• the second user device being configured to:
• retrieve a customer identifier uniquely associated with the user;
• and
• during or after the playing, send the customer identifier and the advertising identifier extracted from the advertising message to the data collection server to monitor the audience of the advertising message.

An apparatus for monitoring an audience of an advertisement over a content distribution system, wherein the advertisement comprises an advertising message associated with digital audio content distributed to a user of the content distribution system, the apparatus comprising a first user device and a second user device, wherein the first user device is configured to:

• receive the digital audio content;
• and
• play the digital audio content with the advertising message,
• extract an advertising identifier from the advertising message, and
• the second user device is configured to:
• retrieve a customer identifier uniquely associated with the user;
• and
• during or after the playing, send the customer identifier and the advertising identifier extracted from the advertising message to a data collection server to monitor the audience of the advertising message, the data collection server being configured to communicate with the second user device over a data communication network.