has released some figures highlighting how the length of online video ad spots can influence consumers’ responses.

The data, taken from’s network and a survey hosted by InsightExpress, found longer pre-rolls delivered higher CTRs but shorter ads performed better in terms of complete views.

It comes as publishers, advertisers and agencies are experimenting with in-stream ad formats to see which suit different types of audiences and campaigns.

The report (pdf) – while not revealing the actual figures - found consumers were 8% more likely to view an entire 15-second ad than a 30-second spot, although the longer format delivered slightly higher CTRs than 5 or 15 second clips.

At the same time, almost two in three consumers (63%) preferred shorter ads – a conclusion backed by other studies.

A YouGov survey in May, for example, found 93% of UK web users were prepared to view pre-roll ads as long as they weren’t over 15 seconds in length. And, of course, YouTube recently opted against pre-rolls altogether in favour of animated overlays that allow the viewer to choose whether to watch the full ads. 

Unsurpisingly, the vast majority of respondents (94%) to’s survey preferred having to watch in-stream ads than facing subscription fees –they are less positive in other surveys when they aren’t presented with an ‘either-or’ question. 

Sixty five percent said they watched ads through to completion, but 22% felt ads should be more relevant.

The report said:

“The length of the ad depends on an advertiser’s goals. Shorter ads work best for advertisers seeking to ensure their entire video message is broadcast to consumers. However, if the advertisers wants to maximise CTR then the longer format should be leveraged.”

The study also focused on general consumption of online video content during the first half of this year. It found:

  • 62% of respondents were viewing video online.
  • These viewers were not just young adults – most (69%) were aged 35 or older.
  • 62% of consumers viewed news clips online, followed by movie trailers at 38%. Music videos came in third with 36%.
  • 51% of respondents would view a TV programme on the web if they missed it, but 80% said online video usage did not eat into their TV time.

Lynda Clarizio, president of, said:

“The internet is still seen first and foremost as an information resource. With news clips remaining the most popular type of streamed content, video viewing habits reflect that status.

“But it will be interesting to see how viewership evolves with the rise of social networks, more diverse video content, increased interactive gaming, and other such advances in online entertainment. I think we may see a shift in usage toward recreation; these latest figures certainly hint at that trend.”

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