The study also predicted that in 2013 digital advertising spending will reach $113.5 billion globally, 14.6 percent more than 2012. The figure represents more than 21 percent of all measured advertising investment. In the 2013 forecast, North America once again ranks first with an estimated $42.8 billion in digital ad spend; Asia-Pacific follows with $36.8 billion, followed by Western Europe with $26.6 billion.

In the U.S., digital advertising spending reached $35.4 billion in 2012, a 23 percent share of the overall domestic market and a 10 percent increase over the previous year, according to the study. This year those figures are expected to reach $39.7 billion for a 25.4 percent share and a 12 percent increase over 2011.

The report also includes commentary on the current state of various digital marketing developments and offers insightful observations on the evolution of digital communications and the inherent implications for marketers.

“The internet no longer belongs to the old world and eastern Asia, nor does it depend upon evolution of infrastructure conceived a generation or more ago, but instead reaches every continent and economically active individual,” Norman wrote in his introduction to the annual report. “Ken Olsen, founder and CEO of Digital Equipment said in 1977, ‘There is no reason for any individual to have a computer in his home.' It turns out that he may, inadvertently, have been right. Why have a computer in your home when you can have computing anywhere you like?”

Norman's essay also addresses the issue of the rise and impact of online video and states: “Tablets created an entirely new and original mechanism of media consumption in less than three years. Tablets combine the display quality of HDTV, the interactivity of the PC and the location awareness, touch interface and app ecosystem of the mobile phone. Media is being re-imagined for the tablet and is increasingly seen as the future home of what we have always described as the print industry, the decline of which is precipitous with ever-fewer exceptions.”

Eoin Treacy's view As the way in which we consume media evolves so is the manner in which advertisers target our attention. The online world offers advertisers a unique opportunity to cater their offering to specific demographics. This has given rise to incredible success stories such as Google. Facebook has more recently attempted to encroach on the sector but has yet to demonstrate Google's earnings power.

Against this background, what might be considered the conventional advertising sector caters its offering to the demands of how people now spend their time consuming media. What is particularly interesting is that the three largest companies WPP, Publicis and Omnicom, are also growing aggressively outside their domestic markets.

Google's international revenues overtook those of the US as early as 2009 and both continue to expand. The share rallied particularly impressively from its November lows to post new all-time highs but has probably entered a process of mean reversion as it unwinds the short-term overbought condition.

UK listed WPP's (DY3.09%) is a former constituent of the S&P Europe 350 Dividend Aristocrats. Its revenues are now split almost equally between Europe, North America and Asia Pacific. The share has probably also entered a process of mean reversion.

North America still represents more than half of France listed Publicis' (1.73%) revenue but Asia Pacific and BRIC represent its fastest growing markets. Its chart pattern shares a high degree of commonality with WPP's

The Americas represented more than half of Omnicom's (2.72%) revenue in 2012 but its Asian segment overtook EMEA ex-UK in 2011 and remains its fastest growth market. Omnicom broke out of a 12-year base in January. Considering the performance of other shares in the sector, the prospect of mean reversion has increased, but a sustained move below the 200-day MA, currently near $52.50, would be required to question the medium-term bullish outlook.