If correct, this represents a sudden jump to life for OTT video advertising after being initially slow to follow the rapid growth of ad-free subscription VoD (sVoD) services such as Netflix, Amazon and Hulu provide. It also defies earlier predictions, although one or two analyst groups were right on the money with their forecasts early in 2017. Forrester for example identified 2017 as the year when ad-supported OTT would finally take off after being slow initially to gain traction simply because the associated services lacked compelling content at all comparable with sVoD. While such services provided little more than lower tier user generated or web-only content they failed to attract the concentration of eyeballs that would interest advertisers.

But that all changed with the advent of serious linear OTT services such as AT&T’s DirecTV Now and DISH Network’s Sling TV service in the US or Sky’s Now TV in several European countries including the UK and Germany. Meanwhile Google’s YouTube and Hulu have also entered the fray with live streaming OTT services that are attracting ad money. This has put major commercial weight behind wholly or partially ad-supported linear OTT offerings, explaining the rapid OTT ad revenue growth charted by SpotX.

The site did not disclose the absolute numbers but in any case they do not correlate that closely with other sources. For example, the portal Statistica.com estimates global TV advertising revenues at around $180 billion for the year 2017 compared with about $26 billion for online video advertising, which is under 15% rather than the 30% cited by SpotX. But comparisons between such surveys are notoriously tricky because they count the market in different ways, some including revenues associated with ads in the web sites of print publications not normally rated as dedicated OTT video.

Nevertheless, while sVoD will remain the primary engine of OTT revenue growth for the foreseeable future, the rapid rise of linear OTT will make a fast-growing impact through direct subscriptions as well as pay per view to some extent and also advertising. Indeed, according to research firm Ovum, subscription OTT services that are driven by linear streaming rather than on demand catalogues are now the fastest growing segment of OTT video. They currently account for about 20% of the global OTT market but this will rise to about 35% by 2022, according to the firm.

What is undeniable is that global OTT revenues as a whole are climbing steeply and are set to continue doing so. A report just out from Digital TV Research covering 138 countries forecasts that worldwide annual revenue from OTT services will grow from about $36 billion in 2016 to $82 billion by 2022 even though pay TV revenues as a whole will decline gently over that period. This highlights how OTT is taking an ever-greater slice of the total pay TV revenue pie, set to rise from 15% in 2016 to 28% in 2022.