Just half of US marketers say TV will rank among their top five channels for advertising spending in three years' time, down from 57% today, as digital spending increases, according to a survey by Bain & Company. The result from more than 600 US marketers "marks the first time we have seen a decline in TV's appeal when we asked marketers which media comprise their five largest advertising channels" in the coming years, said co-authors Danny Hong and Charlie Kim, partners in Bain's Media practice.