According to new research by Advertising Age, revenue at digital specialists soared by 26.8 per cent.
At the same time, agencies of all disciplines reported an average revenue growth of 10.2 per cent from digital.
Goodby, Silverstein & Partners in San Francisco, whose client roster includes HP, said digital now generated 52 per cent of the agency's income.
Major media companies are mirroring the trend. WPP said worldwide digital revenue for its Group M specialist division had risen 53 per cent to $238 million.