The Interactive Advertising Bureau (IAB) this week released its numbers for ad spend in the US in 2016, and for the first time since the organization began tracking digital ad spend in 2004, spend on digital ads has surprassed spend on television ads.

The milestone is one that industry analysts and observers have been waiting for and 2016 also brought with it another milestone: for the first time, mobile ads produced more revenue than desktop ads.

All told, digital ad revenue in the US hit a record $72.5bn last year, up from $59.6bn in 2015. Mobile ads were responsible for $36.6bn of that, a massive 77% year-over-year gain.

A good portion of mobile’s gains were due to the growing popularity of mobile video ads. Spend on those skyrocketed by 145% year-over-year to reach $4.2bn, which helped fuel a 53% year-over-year jump in digital video ad spend overall. That figure now stands at $9.1bn.

Spend on social ads, which in recent years have become a staple of many advertisers’ digital campaigns, grew 50% to $16.3bn. Even search managed to produce a 19% gain to reach $35bn in spend.

According to the IAB, mobile’s ascendency across all digital channels is not surprising. “This increasing commitment [to mobile] is a reflection of brands’ ongoing marketing shift from ‘mobile-first’ to ‘mobile-only’ in order to keep pace with today’s on-the-go consumers,” IAB president and CEO Randall Rothenberg stated. 

“In a mobile world, it is no surprise that mobile ad revenues now take more than half of the digital market share,” IAB EVP and CMO David Doty added.

The rich get richer

While digital’s eclipsing of television in terms of ad spend is no doubt good news for the digital economy generally, not everybody is benefiting equally from the growth of digital ad spend. By most estimates, two companies, Google and Facebook, have realized the vast majority of ad revenue growth, leading some to label the two companies a duopoly.

According to Digital Content Next’s Jason Kint, Google and Facebook took 89% of the growth last year. Brian Wieser of Pivotal Research estimates that amazingly the two companies were the beneficiaries of close to 100% of the growth.

The IAB disputes such claims. “73% of revenues in Q4 came from the top 10 digital companies, but they only contributed 69% of the growth,” the IAB’s Doty told AdAge. “That means 31% of the growth came from companies outside the top 10.” He also stated that some estimates count revenue outside of the US and don’t account for traffic acquisition costs.

But even if the estimates of how much Google and Facebook are taking as the digital ad spend pie grows are slightly exaggerated, it’s clear from the companies’ financial reports that advertisers are funnelling increasingly large sums of money to the two internet giants.

At the same time, other notable players, like Twitter, are losing. The still-popular microblogging platform has finally managed to grow its monthly users by a meaningful amount, but despite user growth Twitter just reported its first quarterly revenue decline and acknowledged that it is facing “revenue headwinds.”

While Google and Facebook face some challenges of their own, including an advertiser boycott and criticism over fake news, every indication is that the two companies, official duopoly or not, will continue to dominate internet advertising. Whether that’s ultimately a good or bad thing for digital ad economy remains to be seen.

For more digital marketing and ecommerce data, download the Econsultancy Internet Statistics Compendium.