• by Joe Mandese  @mp_joemandese, July 9, 2014

Thanks to some quadrennial effects -- especially the World Cup and the Winter Olympic Games -- the rate of global advertising growth will more than double this year, according to an updated outlook published this morning by the media marketplace analysts at eMarketer.

“Several factors will drive this year's growth in total media ad spending -- not only the worldwide advertising frenzies attached to the World Cup and the Winter Olympics, but also the steady increases in online and mobile advertising as consumers globally shift their attention to digital devices,” the report says, estimating that the global ad economy will expand 5.7% this year vs. an expansion rate of 2.6% in 2013.

Based on that level of growth, eMarketer forecasts that worldwide ad spending will top the half trillion dollar mark this year, totaling $545.4 billion.

While digital continues to be a major contributor to the global ad expansion -- reaching 25% of total expenditures this year -- its rate of expansion is actually slowing down, according to eMarketer’s projections. Worldwide digital ad spending is projected to grow 16.7% this year -- up from a growth rate of 14.8% in 2013, but it will begin to contract steadily over the remaining five years of eMarketer’s current outlook. But since it will continue to expand faster than non-digital media, eMarketer projects digital’s share of total ad spending will also continue to climb, reaching nearly a third (32.3%) of global ad volume by 2018.

“Within the digital category, advertising on tablets and smartphones continues to be a key catalyst for growth,” the report predicts. “Worldwide mobile ad spending will increase 84.7% in 2014 to reach $32.71 billion this year, totaling nearly one-quarter of all digital advertising spending (which includes paid media spending on ads of any format delivered to any internet-connected device).”