Digital, in advertising, is the label for media delivered to internet-connected devices and logged by software, one impression, click or view at a time. Search results, social feeds, banners, online video, podcasts and most streaming television fall inside it. The term exists because buyers and forecasters needed one line to separate that spending from traditional media, meaning linear television, print, radio and billboards, which are sold by schedule and measured through panels and audits. By most counts the category now takes close to three quarters of global advertising revenue. Where its boundary sits depends on who is counting.

What makes media digital

Three technical traits define the category. Delivery runs over internet protocol (IP) networks to a browser, app, smart TV or connected speaker, not through a broadcast signal or a printing press. Each exposure is recorded by an ad server, so volume is counted from logs rather than estimated from a sample. And the ad can be chosen for a single device at the moment of delivery, which makes the audience addressable and allows pricing per thousand impressions (CPM), per click (CPC) or per action (CPA).

In practice, an advertiser or its agency sets up a campaign in a buying tool, either a search or social platform's own ad manager or a demand-side platform (DSP) for the open web, where publishers offer inventory through supply-side platforms (SSPs). When a page, app or streaming show requests an ad, an auction or a pre-agreed deal picks one, the ad server returns the creative and logs the impression, and measurement tags report viewability, clicks and conversions. Agency trading desks and in-house teams run the buy side. The sell side is concentrated: the ten largest companies took 84.1% of US internet advertising revenue in 2025, up from 80.8% in 2024, according to the Interactive Advertising Bureau (IAB) and PwC.

How the category is counted

Forecasters and trade bodies draw the line in at least four ways.

By format. The IAB/PwC Internet Advertising Revenue Report, compiled since 1996, splits US revenue reported by companies selling advertising online into search, display, digital video, audio and other formats such as classifieds. Connected TV (CTV) is included, which the report describes as TV-like, typically long-form content delivered over the internet to a smart TV or streaming device. Social media, commerce media and programmatic cut across those formats, which is why social at $117.7 billion, search at $114.2 billion and programmatic at $162.4 billion add up to more than the $294.6 billion total for 2025. The figures come from company submissions and public filings, and PwC provides no audit or assurance.

By seller. Magna's June 2025 global forecast put digital pure players at $715 billion of a $979 billion market, about 73%, and traditional media owners at $264 billion, according to TheWrap. The second figure includes those owners' streaming, digital audio and digital publishing sales, about a quarter of their revenue. A broadcaster's streaming ad on a smart TV is therefore traditional to Magna and digital to the IAB.

Both at once. WPP Media reports two numbers. Its June 2025 midyear forecast expected pure-play digital to take 73.2% of global ad revenue in 2025, rising to 81.6% once streaming television, digital out-of-home and digital print were added. The 8.4-point gap is a rough measure of the disputed territory.

By statute. Legal definitions are narrower. Maryland's Digital Advertising Gross Revenues Tax, applied to tax years beginning after December 31, 2021, covers "banner advertising, search engine advertising, interstitial advertising, and other comparable advertising services" on a digital interface, excluding interfaces run by broadcast and news media entities. A technical bulletin from the state comptroller dated July 11, 2025 reads that list as limited to advertising that is both programmatic and visually conveyed, so purely audio ads fall outside. Rates run from 2.5% to 10% depending on a company's global revenue.

Origin and evolution

The word predates the medium by five centuries. It entered English in the mid-15th century from the Latin digitus, finger, because numbers below ten were counted on the hands, according to the Online Etymology Dictionary. The sense "using numerical digits" dates from 1938, and its application to computers from about 1945.

Advertising arrived under other names. AT&T's banner on HotWired went live on October 27, 1994. The trade body formed two years later was the Internet Advertising Bureau, and US spending in its first year was about $260 million. On April 10, 2001, it renamed itself the Interactive Advertising Bureau to take in wireless and interactive television sellers. By the middle of the decade "digital" had become the umbrella. Publicis Groupe agreed on December 20, 2006 to buy Digitas for $1.3 billion, with chairman Maurice Levy saying the deal would "really boost our presence in the digital marketplace".

The crossover dates followed, and they depend on the source. Internet advertising took 23.5% of the UK market in the first half of 2009, ahead of television's 21.9%, according to Internet Advertising Bureau figures reported by Press Gazette. In the US, eMarketer forecast in March 2016 that digital would overtake TV in 2017. Magna later reported that it had already done so in 2016, with $70 billion against $67 billion for national and local television. Magna's June 2019 forecast had digital taking 51% of global ad sales that year, or $304 billion.

Why the label matters

US revenue grew 13.9% to $294.6 billion in 2025, and spending across 30 European markets rose 10.5% to EUR 131.1 billion.

The label also carries legal weight. The EU's Digital Markets Act lists "online advertising services" among its core platform services, and the ad services of Alphabet, Amazon and Meta are each designated under it. Tax has followed. Canada's 3% digital services tax, applied retroactively to 2022, was rescinded on June 29, 2025, a day before first payments were due. Google had added a 2.5% surcharge on ads served in Canada from October 1, 2024, and Amazon passes such taxes on as a Regulatory Advertising Fee itemised by destination country. Washington state began charging sales tax on advertising services, including search engine marketing, on October 1, 2025. A 2026 law, Engrossed Substitute Senate Bill 6346, repeals several of the new service taxes from January 1, 2029 but leaves advertising taxable, according to the law firm Ballard Spahr.

Limitations and disputes

Comparability is the first problem: totals from the IAB, Magna and WPP Media cannot be set side by side without adjustment. Streaming is the largest contested area. WPP Media's December 2025 forecast counted streaming inside television, $43.9 billion of $167.4 billion in TV revenue, according to Marketing Brew, while ranking commerce advertising, at $178.2 billion, ahead of TV for the first time. Broadcaster bodies such as Thinkbox in the UK and ThinkTV in Australia group broadcaster streaming with linear TV, treating the two as the same medium delivered twice. Most trackers file digital out-of-home screens under outdoor.

Concentration is the second. Growth in the category is largely growth at the ten companies holding 84.1% of US revenue, and statements about "digital" often describe their results.

The third is the assumption that digital means measurable. A server log records that an ad was served, not that a person saw it, and platform figures are largely self-reported. DoubleVerify reported that CTV fraud schemes rose 140% in the first quarter of 2026 compared with a year earlier.

Legal definitions remain contested. On August 15, 2025 the US Court of Appeals for the Fourth Circuit struck down, on First Amendment grounds, Maryland's ban on itemising the tax on invoices. The tax itself stands, since earlier challenges to it were dismissed on procedural grounds, according to PwC.

Some forecasters now question the label altogether. WPP Media replaced the old split with four groupings: Content, Commerce, Location and Intelligence, in its June 2025 forecast.

Not the same as

Digital marketing - the wider discipline, covering owned and earned channels such as email, websites and search engine optimisation as well as paid media.

Online or internet advertising - near-synonyms from the 1990s. The IAB/PwC report keeps "Internet" in its title, while the IAB's announcement of the 2025 figures spoke of digital ad revenue.

Programmatic - an automated way of trading inventory, not a channel in itself. It also reaches CTV, audio and digital out-of-home.

Digital television and digital radio - broadcast transmission standards. US full-power stations ended analogue broadcasts on June 12, 2009 and the UK completed its switchover in October 2012, yet digital terrestrial television and digital audio broadcasting (DAB) radio are still counted as television and radio.

Recent developments

The IAB marked its 30th year with the 2025 revenue report on April 16, 2026. Chief executive David Cohen said the growth "reflects a market that has reoriented around performance channels". In July 2026, IAB Europe's chief economist Daniel Knapp described digital advertising as "sales infrastructure, shelf space and shopfront at once".

On June 16, 2026, WPP Media raised its 2026 global forecast to $1.3 trillion, growth of 8.9%, and put traditional and generative search at 21.8% of all advertising revenue. In the US, the IAB lifted its 2026 forecast to 12.3% growth in September, with CTV expected to grow 15.6% and linear television to shrink 1.5%.

Newer surfaces are arriving. OpenAI's ChatGPT ads business passed a $1 billion annualised run rate less than 200 days after its February 9, 2026 US launch. EMARKETER expects US spending on AI-related advertising to reach $68.25 billion by 2030, up from $32.03 billion in 2026. More than 80% of the 2026 figure is search advertising placed beside AI-generated answers rather than inside chatbots.

Timeline

  • Mid-15th century: "Digital" enters English from the Latin digitus, finger
  • 1938: The sense "using numerical digits" is first recorded
  • October 27, 1994: AT&T's banner ad runs on HotWired
  • 1996: The Internet Advertising Bureau is founded and the IAB revenue report begins
  • April 10, 2001: The organisation renames itself the Interactive Advertising Bureau
  • December 20, 2006: Publicis Groupe agrees to acquire Digitas for $1.3 billion
  • June 12, 2009: US full-power television stations end analogue broadcasts
  • First half of 2009: Internet advertising takes 23.5% of the UK market, overtaking television
  • October 2012: The UK completes its digital television switchover
  • March 2016: eMarketer forecasts US digital ad spending will overtake TV in 2017
  • 2016: US digital ad sales of $70 billion pass TV's $67 billion, according to Magna
  • June 2019: Magna forecasts digital will take 51% of global ad sales
  • February 12, 2021: Maryland's legislature enacts the Digital Advertising Gross Revenues Tax by veto override
  • January 1, 2022: The Maryland tax applies to tax years from this date
  • May 2, 2023: The EU Digital Markets Act becomes applicable
  • September 6, 2023: The European Commission designates six gatekeepers
  • October 1, 2024: Google begins a 2.5% surcharge on ads served in Canada
  • June 10, 2025: WPP Media puts pure-play digital at 73.2% of global ad revenue and introduces a new taxonomy
  • June 16, 2025: Magna puts digital pure players at $715 billion of a $979 billion market
  • June 29, 2025: Canada rescinds its digital services tax
  • July 11, 2025: Maryland's comptroller issues Technical Bulletin No. 59
  • August 15, 2025: The Fourth Circuit strikes down Maryland's pass-through prohibition
  • October 1, 2025: Washington state begins taxing advertising services
  • December 9, 2025: WPP Media puts 2025 global ad revenue at $1.14 trillion
  • February 9, 2026: ChatGPT ads launch in the US
  • April 16, 2026: IAB/PwC reports US internet ad revenue of $294.6 billion for 2025
  • June 16, 2026: WPP Media forecasts $1.3 trillion in global ad revenue for 2026
  • July 2026: IAB Europe reports EUR 131.1 billion in European digital ad spend for 2025
  • September 2026: IAB lifts its 2026 US ad growth forecast to 12.3%

Summary

Who: Advertisers and agencies on the buy side; search engines, social networks, retailers, publishers and streaming services on the sell side; and the bodies that count the category, including the IAB and PwC, IAB Europe, Magna and WPP Media. Legislators and tax authorities in Maryland, Washington state, Canada and the EU have written their own definitions.

What: The industry label for advertising delivered to internet-connected devices and logged by software, typically search, display, online video, audio, social and CTV. It is distinct from traditional media such as linear TV, print, radio and static outdoor, although forecasters disagree over where streaming, digital out-of-home and digital print belong.

When: The word entered English in the mid-15th century and took its numerical sense in 1938. The first banner ad ran on October 27, 1994, digital overtook television in the UK in 2009 and in the US in 2016 by Magna's count, and Magna forecast that it would pass half of global ad sales in 2019.

Where: Worldwide. The most cited measurements are the IAB/PwC report for the US, IAB Europe's study of 30 European markets, and the global forecasts from Magna and WPP Media.

Why: The label separates software-delivered, addressable media from scheduled broadcast and print, and it now covers roughly three quarters of global ad revenue. Budgets, regulation and taxes attach to it, which is why the inconsistent boundaries between trackers, the concentration of revenue in a few platforms and the gap between logged and verified exposure matter.