Hence, with a finite funding pool available for advertising, as more delivery agents of advertising in the Mobile and Social space as well as more claimants of advertising revenue come into play, existing players must surely experience the flip-side of the success of a new agent or claimant.
The loss of advertising revenue to Google by others (Yahoo) in the past will in the same way affect Google e.g. Facebook, Pinterest, etc., unless the pool size is enlarged at the same rate of displacement.
With this in mind, I suppose that it is no surprise that Google is lessening its dependency on advertising revenue and expanding in other directions.
Although, YouTube is planning to make a concerted effort to monetize the platform to a far greater extent. Hence, one of the reasons for +Susan Wojcicki moving from Google having made advertising the success that it is, for a repeat performance. So you never really know.
It has occurred to me that Google has a quiet vested interest in expanding the number of people with access to the internet via Android One and Project Loon to partly offset the effect of declining revenues in mature markets, but the newbies are likely to have smaller budgets, the overall effect of which may not compensate adequately.