Spill Viewing and Overlap Markets are two closely related but distinct concepts.

Unlike the distinct OzTAM and Regional TAM TV ratings service databases, which could only be analysed separately, VOZ now offers the opportunity to analyse metropolitan and regional markets together in a single, national Total TV database. This requires additional consideration on when to include or exclude spill viewing when analysing VOZ data.

Spill Viewing

Spill viewing is a Free-to-Air broadcast TV-only concept that relates to viewing of broadcast channels transmitted from a market that is outside of the market being analysed. Note in the TAM broadcast TV ratings service, program audiences are always to local market broadcast TV channels, and therefore no spill viewing is included.

Overlap Markets

Market areas are defined by the ACMA broadcast TV licence areas. Some of these licence areas overlap between metropolitan and regional markets, specifically:

• Sydney/Newcastle
• Melbourne/Gippsland
• Brisbane/Northern Rivers
• Brisbane/Maryborough

The viewing by people in these distinct overlap areas contributes to the market that the broadcast originates from as local market viewing. For example, people viewing broadcast TV channel Seven Sydney within the Sydney/Newcastle overlap area will have that viewing contribute to the Sydney Market as local market viewing. Conversely, people viewing broadcast TV channel Seven Sydney within the Sydney/Newcastle overlap area will have their viewing contribute to the NNSW Market as spill viewing.

The following examples provide guidance for analysing viewing within VOZ:

• The viewing to a broadcast that originates from Sydney by a viewer in the regional Wollongong market is spill viewing (noting that Sydney and Wollongong do not overlap meaning this is unambiguously spill viewing).

• In the case where markets do overlap, such as when there is viewing to a broadcast that originates from NNSW Northern Rivers market by a person in the Brisbane markets:
  • If that person is within Brisbane but not within the overlap area, then their viewing to the NNSW Nortthern Rivers market broadcast is Spill Viewing.
  • If that person in Brisbane is specifically within the Brisbane/Northen Rivers overlap area, then their viewing to the NNSW Northern Rivers market broadcast is:
    • Spill Viewing if reporting the Brisbane market
    • Local Market Viewing if reporting the NNSW Aggregate market.

Importantly, the broadcast TV quarter hour files from the VOZ service excludes ‘spill viewing’.