Google, driven primarily by its YouTube site, ranked highest for video viewing sessions, attracting 34.4 million people watching 2.8 billion videos.
ITV served the most online video ads, 62.6 million ads delivered to 4.6 million unique users.
ComScore generated the figures using its Video Metrix 2.0 system, which launches today, designed to "better align with the realities of today’s online video landscape".
Mike Read, ComScore senior vice president and managing director for Europe, said the consumption patterns and economics of online video were evolving.
"Video measurement needs to be just as innovative in order to capitalize on new monetisation opportunities and help pave the way for digital media convergence with traditional media," he added.
ComScore consider one session to be a period of time with continuous video-viewing. A session ends, if a viewer is inactive for 30 minutes.
FW: comScore Launches Video Metrix 2.0 in the UK to Measure Evolving Online Video Landscape
Top 5 UK video content properties by viewing sessions
|Property||Viewing Sessions (000)||Total Unique Viewers (000)||Videos (000)|
|Total internet : Total audience||963,971||34,720||6,032,002|
Top 5 UK video ad properties by unique video viewers
|Property||Total Unique Viewers (000)||Video Ads (000)|
|Total Internet : Total Audience||23,007||527,132|
|SpotXchange Video Ad Network||7,218||28,952|
|Joost Video Network (by Adconion)||5,757||20,469|
Video ads include streaming-video advertising only and do not include other types of
video monetization, such as overlays, branded players, matching banner ads, homepage