The CMO tenure data is from analysis of the tenures of CMOs from 100 of the top US advertised brands as of December 31, 2015.

Greg Welch, consultant in the Spencer Stuart Marketing Officer Practice, said: "It’s easy to focus solely on the fact we're seeing shorter CMO tenures, which is telling, but I think equally compelling is that 30 companies of the 100 in our study have new senior marketers at the helm."

"The industry-wide impact of having nearly one-third of the top CMOs new to their roles is significant, given the incredible influence and buying power that today’s top CMOs wield."

Of the 30 new CMOs, 22 ( 73%) are moving into the top marketing job for the first time. This is consistent with the remaining companies on the list, where 51 of the 70 CMOs ( 73%) were first-time CMOs when they were named to their current role.

Diversity is still an issue: 10 of the new CMOs ( 33%) are female, while of the remaining CMOs on the list, 14 of 70 ( 20%) are female. Four of the 30 new CMOs are diverse ( 11%), compared with eight of the 70 remaining CMOs ( 12%).