What time lengths should I use for my TV campaign?
In terms of generating brand-linked ad awareness, there is no consistent cost efficiency of using longer or shorter time lengths; and different ad lengths communicate similarly in terms of primary message levels.
In terms of persuasion, there is likely to be some cost efficiency advantage to using the 15-second, due to the fact that the 100 air-time equivalent GRPs generate more exposures.
On the other hand, longer ads allow more time for engagement and so will be more appropriate for complex impressions.
These last two points highlight the importance of...