Amid the annual five-year PwC outlook for US media (its reports on Australia and NZ have been released in the past week) was the stunning forecast that ad spending on the 2016 US presidential and congressional elections will hit US$4.4 billion and that this (with the Olympics on NBC) will be enough to boost TV ad spending in America by 4.4% in 2016.

The main message from the outlook is the continuing rapid growth in mobile advertising to the point where PwC says the surge in mobile video will push digital advertising revenues to US$75.3 billion in 2017, topping the $70.4 billion going to US TV broadcasters. So the biggest advertising gains are expected in mobile advertising, which was responsible for 34.7% of total internet ad revenue in 2015 at $20.7 billion and is projected to rise to 49.4% by 2020.

And nowhere is that best illustrated by the rapid growth in mobile ad in the current US election campaign. PwC forecasts television advertising spending will reach US$4.4 billion for this election, from US$3.8 billion in 2012 — with spending on digital advertisements projected to grow tenfold to more than US$1 billion.

Of the US$4.4 billion, an estimated $3.3 billion will be spent with local TV stations in the US. On top of this is the so-called free advertising candidates such as Donald Trump, Bernie Sanders and Hillary Clinton have gained from media coverage of rallies, debates and set piece speeches. Trump’s “free” coverage was valued at more than US$600 million in May, for example, according to estimates issued last week by an analytics firm.