ZenithOptimedia, which compiled the forecast, said motors, finance, airlines and fast-moving consumer goods were the main categories investing in TV, which is up 8% for the year to date and is expected to increase by a similar amount in December. Jonathan Barnard, the head of forecasting at ZenithOptimedia, said: "December TV spending is particularly heavy this year because categories targeting young affluent men crowded out other categories, such as general retailers, during the Rugby World Cup."