Carlton To Change Rate Policy?

Carlton is proposing to change the way it calculates its station cost per thousand figures, moving from the weighting of messages by ratecard to their weighting by spot length (ie. pro rata). This would mean that 10 second impacts would be calculated at a third of a 30 second impact, rather than the usual half. A change in method would mean Carlton’s messages would fall, thus increasing their CPTs ;LWT already calculates CPTs this way.