[The 7 Principles of Google Marketing, posted by Nial]
Do you know how the advertising agency came about? Let me quote from the now fabled tome "The Shocking History of Advertising!":
The original agents had owed their allegiance to the newspapers rather than the advertisers; they had been debt-collectors at best and fee-snatchers at worst. Now agents began to identify themselves with the advertiser. The number of newspapers was so great that only a specialist could keep track of them all, and form a view as to their usefulness. Some of the leading agents were even undertaking to prepare the advertiser's copy and illustrations for him.
So yes, the first agencies were media agencies and then eventually some bright spark realised that could provide the content as well. In fact, it was N.W. Ayer and Son in Philadelphia that became the very first full service agency.
Google is the biggest broker of online media. The acquisition of DoubleClick takes them into display and tracking, and they've been quite open about their intention to roll out their model into other media.
Yesterday it was reported that Google has hired Andy Berndt, co-president of Ogilvy &Mather New York, to lead a new unit dedicated to collaborating with marketers and agencies.
Google is a value chain creeper - it moves along its industry value chain, eating up the value, and this move is no different. Accenture has already argued that Google functions in some aspects like an agency. It's small step from optimising copy based on click-throughs to advising on how to write effective copy.
Will Google start making films? This seems extremely unlikely, but then who says that's what ad agencies are going to look like in the future. Agencies are shifting away from 'advertising' and re-inventing themselves as 'ideas companies' to better address the needs of modern advertisers and connected consumers.
[Update: On a tangentially related note, Google today announced their move into rich media with Google Ad Gadgets.]