Online Advertising Market Size & Share Analysis - Growth Trends and Forecast (2026 - 2031)

Global Online Advertising Market Trends and Insights

Retail Media Networks Monetization Driving Closed-Loop ROAS for CPG Brands

Retail media networks grew into strategic profit centers in 2025 as Amazon Ads, Walmart Connect, and Instacart Ads jointly attracted roughly USD 50 billion in annual spend. Brands value the closed-loop attribution that links on-site impressions to confirmed checkouts, eliminating guesswork around viewability proxies. Bain and Company calculated three-to-five-times higher return on ad spend for retail media versus open-web display in 2025. Sam’s Club extended its Member Access Platform by giving suppliers transactional data for granular audience segments capabilities that conventional publishers cannot match. As a result, legacy display outlets lose budget share, and inventory supply is concentrating in vertically integrated ecosystems that own both ad server and point of sale.

Increasing Smartphone Penetration Boosting Mobile Ad Impressions Globally

Global smartphone subscriptions hit 6.8 billion in 2025, lifting mobile to 63.79% of total spend and giving advertisers an always-on screen that dominates daily media time.^{[1]Ericsson, “Mobility Report,” ericsson.com} Users average 4.8 hours per day on handheld devices more than double desktop engagement. Cheaper 5G phones in India, Indonesia, and Nigeria are enlarging addressable audiences where desktop ownership remains below 20%. Google’s Performance Max campaigns generated 18% more conversions per dollar on mobile placements than desktop during H1 2025, reinforcing advertiser preference for mobile-first creative strategies.

Shift of TV Budgets to Connected-TV Platforms Expanding Programmatic Video Inventory

Linear television spend in the United States fell 8% year-over-year in 2025, freeing USD 7 billion that migrated to connected-TV environments offering audience targeting and real-time reporting. Amazon introduced ads on Prime Video in 2024, instantly adding 200 million ad-supported viewers. Roku’s platform revenue grew 16% in 2025, with programmatic channels contributing 55% of ad sales compared with 42% in 2023. Advertisers gain household-level segmentation and 90% completion rates that broadcast cannot replicate, accelerating cord-cutting and pressuring traditional network margins.

5G-Enabled Immersive Video Ads Accelerating Spend in South-East Asia

5G subscriptions in South-East Asia passed 150 million in 2025, unlocking high-definition vertical video and augmented-reality try-ons that were bandwidth-constrained on 4G.^{[2]GSMA Intelligence, “Mobile Economy Asia Pacific 2025,” gsma.com} TikTok reported 22% higher engagement for immersive ads in Indonesia versus standard in-feed units. Telkomsel’s partnership with Google enables zero-rated video inventory, extending reach among price-sensitive users while preserving first-party behavioral insights.^{[3]Telkomsel, “Google Partnership,” telkomsel.com} This convergence of network speed, sensor-rich devices, and creative tooling raises brand appetite for experiential formats across South-East Asia.

Signal-Loss from Third-Party-Cookie Deprecation in the European Union Undermining Targeting

Google’s staged phase-out of third-party cookies removed cross-site IDs for 65% of European web users by mid-2025. IAB Europe recorded a 23% decline in programmatic CPMs for open-web publishers during H1 2025. Criteo’s European revenue slid 11% year-over-year in Q2 2025 as commerce-data partnerships failed to fully replace deterministic cookies. Privacy Sandbox APIs remain below 30% adoption as of December 2025, widening the performance gap between walled gardens and open web.

Digital-Services Taxes in the United Kingdom and France Squeezing Platform Margins

The United Kingdom’s 2% and France’s 3% levies on gross digital-ad revenue extracted roughly USD 1.2 billion from platform operators in 2025. Smaller supply-side platforms such as PubMatic and Magnite absorbed 4%–6% hits to net income, forcing fee hikes to advertisers or lower revenue shares to publishers. Uncertainty around a wider EU-wide tax in 2027 delays infrastructure investment and nudges some vendors to relocate legal entities.

Segment Analysis

By Advertising Format: Video Accelerates as Short-Form Monetization Matures

Video accounted for 29% of 2025 spend and is growing at a 10.59% CAGR, outpacing the broader online advertising market. YouTube Shorts logged 70 billion daily views in 2025, and Alphabet activated mid-roll monetization in Q2, unlocking fresh inventory.^{[4]Alphabet, “Q2 2025 Earnings Call,” abc.xyz} TikTok’s in-feed units generated USD 14.5 billion in 2024 revenue, expanding 35% year-over-year. Advertisers embed product tags inside video frames for one-tap purchases, blending commerce with entertainment. Search retained a leading 39.16% share in 2025 because intent-rich queries convert two-to-three times better than interruptive placements, though growth moderates as incremental query volume plateaus. Display faces structural headwinds from cookie deprecation, steering spend to contextual placements that carry lower CPMs. Email remains niche for direct-to-consumer brands using owned lists to bypass platform fees, yet inbox saturation and tightening spam filters cap scale.

A second wave of innovation ties video directly to transaction data. Amazon’s Fire TV integrates shoppable overlays tied to Prime checkout, while Meta’s Advantage+ generates video creatives on the fly, trimming CPA by 12% in pilot studies. As video merges with commerce and automation, the format’s share within online advertising market size is poised to keep widening over the forecast horizon.

Note: Segment shares of all individual segments available upon report purchase

By Platform: Connected-TV Disrupts Linear as Addressability Scales

Mobile maintained 63.79% of spend in 2025 because smartphones accompany users throughout the day and drive multisession behavior. Connected-TV share remains smaller but rises at an 11.09% CAGR, the fastest platform trajectory within the online advertising market. Amazon’s Prime Video introduced ads to 200 million global viewers, temporarily softening CPMs by 12% in Q1 2024 before demand caught up. Roku finished 2024 with 85 million active accounts, and Samsung Ads now reads viewing data from 60 million smart TVs across North America and Europe. Desktop usage declines among younger cohorts who favor mobile-first consumption, though it retains value for workplace B2B campaigns. Other screens such as in-game or digital out-of-home add incremental reach but lack unified measurement, limiting budget flows for now.

Cross-screen identity solutions seek to tie household-level exposure on connected-TV to mobile retargeting. The Trade Desk’s Ventura OS offers a single dashboard for planning across display, audio, and streaming, simplifying workflow for midsize advertisers entering programmatic buying. As addressability improves, connected-TV could challenge mobile for incremental dollars, especially for brand video budgets relocating from broadcast.

By End-User Vertical: Retail and E-commerce Lead as Attribution Tightens

Retail and e-commerce represented 21.53% of 2025 spend and will rise at a 10.84% CAGR, mirroring the expansion of retail media networks. Walmart Connect delivered USD 3.4 billion in fiscal-2025 revenue, up 26% year-over-year. Instacart Ads exceeded USD 1 billion in 2024, capturing trade-marketing budgets directly at the point of purchase. Automotive lifted digital outlays 14% in 2025 to launch new EV models using high-impact video and live streams that bypass traditional dealerships. BFSI leans on mobile-first ads to promote app-based banking and contactless payments. Healthcare remains regulated outside the United States, yet telehealth apps create privacy-compliant channels for condition-specific messaging. Verticals without transaction data, such as broadcast media, face yield compression, making first-party commerce insight the determinant of future share within the online advertising market.

Retailers increasingly extend their data off-site. Sam’s Club and Carrefour sell shopper segments into streaming and social channels, producing omnichannel frequency control. As closed-loop attribution becomes standard, retail and e-commerce share of online advertising market size should keep climbing, squeezing publishers that cannot match purchase-based optimization.

Note: Segment shares of all individual segments available upon report purchase

By Ad Buying Model: Programmatic RTB Extends Lead as Automation Deepens

Programmatic RTB already accounts for 54.28% of 2025 spend and posts an 11.22% CAGR, reinforcing automation as the default workflow. Open-auction liquidity allows long-tail advertisers to enter with sub-USD 1,000 budgets, although small buyers pay higher effective CPMs than enterprise cohorts who negotiate volume discounts. Programmatic guaranteed appeals to brand campaigns seeking placement in premium content under fixed rates but grows slower because supply is finite and publishers prefer yield-maximizing auctions. Manual insertion orders continue for tent-pole events but shrink in share as agencies digitize. Self-serve dashboards from Meta and Google simplify campaign setup for SMBs but push creative burden onto advertisers, making generative AI tools critical.

Independent players innovate to compete with walled gardens. The Trade Desk’s Kokai AI uses large language models to correlate contextual signals with bid modifiers, reducing wasted impressions by 18% for automotive pilots. Magnite posted 31% year-over-year CTV revenue growth in Q3 2025 as streaming apps shifted unsold inventory from direct deals into programmatic pipes. As more impressions pass through automated auctions, programmatic RTB’s share of online advertising market share will likely exceed 60% before 2031.

Geography Analysis

North America contributed 35.19% of 2025 spending, anchored by the United States where per-capita outlay reached USD 650 and Google, Meta, and Amazon absorbed over 60% of budget. Canada rose 9% in 2025, powered by Loblaw’s PC Optimum and Canadian Tire’s Triangle Rewards retail networks. Mexico advanced 12% as Mercado Libre monetized shopper data. While privacy regulation such as the California Consumer Privacy Act lifts compliance overhead, high-value consumers sustain premium CPMs.

Asia Pacific is the fastest-growing region at an 11.37% CAGR. China generated roughly USD 120 billion in 2025 advertising revenue as Taobao and Douyin blended video, commerce, and payments. India, Indonesia, and Vietnam rely on mobile-only users, letting advertisers skip desktop era infrastructure. Japan shifted budgets to connected-TV where NHK and Fuji Television launched ad-supported streaming. South Korea doubles down on super-app ecosystems from Naver and Kakao. Australia’s CartologyAI pushes programmatic audio while New Zealand emulates these models.

Europe faces cookie deprecation and digital-services taxes that damp open-web monetization. Germany, the United Kingdom, and France deliver 55% of regional spend. The United Kingdom still grew 7% in 2025 as brands refuge within walled gardens.^{[5]Advertising Association, “Q4 2025 Report,” adassoc.org.uk} France saw 18% connected-TV growth thanks to Canal+ programmatic ad insertion. Italy and Spain expanded 9% and 8% respectively on back of mobile commerce.

South America added 13% in 2025, with Brazil at 60% of regional spend as Mercado Libre and Magazine Luiza grew retail media. Argentina contracted 5% amid currency stress. Lower per-capita outlay at USD 85 limits upside, and connected-TV trails due to broadband gaps.

Middle East and Africa are smallest yet expanding swiftly. The United Arab Emirates and Saudi Arabia concentrate 70% of Middle East spend. Turkey rose 15% in 2025 despite lira volatility, and South Africa increased 11% on mobile WhatsApp Business placements. Infrastructure bottlenecks restrain high-bandwidth formats but young demographics offer long-run potential within the online advertising market.