Fresh from the announcement of the largest advertising merger, Omnicom and Publicis are now after giants like Google for their advertising. Publicis Chief Executive, Maurice Lévy, said that there are "billions of people" who are always online and are providing data to companies, offer an opportunity for the use of advertising technologies to squeeze billions of pieces of data "in order to come with a message which is relevant to a very narrow audience."

Advertising agencies work hand in hand with companies like Google, Facebook and Twitter, are including sharing data as part of their advertising. The same companies also work directly with companies like Coca-Cola and General Motors.

"Industrywide, you're seeing more and more brands taking in pieces of what they used to pay an agency to do in-house and then spend that with other companies," said Brad Rencher, senior vice president and general manager of digital marketing at Adobe Systems.

"We see the lines have been blurred between the various functions and the various players," Maurice Levy said in an interview. "In this world you have to partner and you have to compete with a lot of players."

Traditional advertising agencies are now under pressure to convey more value for their customers, or else they will be cut out of the equation. Middlemen between the firms and the platforms like television networks, radio stations and online publishers are now preparing for the challenge that lies ahead.