By: Emily Tan

According to Zenith’s Top Thirty Global Media Owners, published today, the two internet giants captured  64% of all the growth in global adspend between 2012 and 2016. 

The report is Zenith’s ranking of the world’s largest media companies, and has been published since 2007. This edition focuses purely on media owners' revenues from advertising, excluding revenues from all other activities. 

Google (under its holding company Alphabet) is, by far, the largest media owner in the world. In 2016, the company earned $79.4bn (£61.52bn) in advertising revenue. This was three times more than the second-largest media owner, Facebook, which reported ad revenues of $26.9bn. 

More recently, Alphabet posted ad revenues of $21.4bn in the first three months of 2017, a growth of 18% despite an ongoing boycott of ads on YouTube. 

As well as Alphabet and Facebook, there are five other pure-internet media companies in the top 30: Baidu, Microsoft, Yahoo, Verizon and Twitter. 

These seven digital platforms generated $132.8bn in internet ad revenue last year, which makes up 73% of all internet adspend and 24% of global adspend across all media. 

Verizon entered the rankings in 2015 when it bought AOL. It currently takes 21st place in Zenith's ranking but after it acquired Yahoo, it could climb to sixth place.

According to Zenith, the fastest growing media owner is Twitter which increased its ad revenues by 734% between 2012 and 2016. 

This growth appears to be slowing down. On Wednesday Twitter reported further declines in its ad revenue which fell 8% in the first quarter of 2017 from the same period a year earlier.

Tencent is the second-fastest growing, having surged 697% during this period. Facebook comes in third with 528% growth while two other media owners have more than doubled in size during that time period: Baidu, which grew 190%, and Sinclair Broadcasting Group, which grew 171%.

Most of the media owners in our ranking – 20 out of 30 – are based in the US. China and Germany each have three media owners in the ranking. Baidu, Tencent and CCTV for China; and Bertelsmann, ProSiebenSat.1 and Axel Springer for Germany.

There are four countries with one media owner each: France (JCDecaux), Brazil (Grupo Globo), Italy (Mediaset) and the UK (ITV).

"Zenith’s new ranking demonstrates just how much the internet advertising platforms are setting the pace for global adspend growth," Jonathan Barnard, head of forecasting at Zenith, said. "Google and Facebook alone have accounted for almost two-thirds of global adspend growth since 2012."