Whitepaper
Advertising Under Pressure: Your guide into Golden Quarter 2026 and beyond
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Online video advertising (OLV) places short- or long-form video ads before, during or after content on websites and apps across the open web, in formats ranging from in-stream pre-roll to full-screen interstitials. It runs across desktop, tablet and mobile, which means it can reach people wherever they are watching rather than only on the television set.
Its appeal is that it carries the emotional weight of broadcast-style creative with the targeting precision and measurement of digital. That combination is why it works at every stage of the customer journey, from first awareness through to re-engaging people who already know you.
The three are easy to conflate but buy differently. Connected TV (CTV) is video watched through streaming apps. Social video sits inside a single platform's feed. Online video is the open web: publisher sites and apps, across every device a person uses through the day. Where CTV owns the living-room moment, OLV engages the viewer across screens — which is what makes it a full-funnel channel rather than a single-moment one.
Because viewing has moved, and budgets are following. Investment in video display in the UK rose 20% to £8.3bn in 2024, outpacing the wider digital ad market, which grew 13%.
Video now takes 64% of all online display spend, up from 51% five years ago. The shift tracks behaviour: every age group under 55 now spends more hours per week watching digital video than linear TV. IAB UK expects the trend to continue, forecasting video display to reach 27% of the digital market by 2027, up from 23% in 2024.
Unlike channels tied to one moment, OLV works from top to bottom. It can build awareness with broadcast-quality creative, support consideration alongside your other media, and re-engage people who have already visited or bought. The catch is that spreading a channel across the whole funnel and every device only pays off if you can recognise the same person as they move, otherwise reach and frequency drift, and measurement fragments.
Rising spend makes online video hard to ignore, but budget follows results, not trends. The question is less should we run OLV? and more how do we run it in a way that drives measurable outcomes?
Find out how Epsilon helps brands plan, activate and measure online video campaigns: Online Video Advertising (OLV) Platform
