The mood is reflected in a new survey carried out by the market research company Advertising Perceptions.
More than 1,800 people, including marketers and agency executives, took part in the survey.
Many said they expected TV, magazines, newspapers and outdoor to suffer most during the next six moths. However, they predicted increases in online, cable TV ad mobile spending.
Audrey Siegel, the client services director at the independent media agency TargetCast, said: "It's not that there is a conversation about not advertising, but there is definitely an air of vulnerabilty and concern."