From CMO Today, a Wall Street Journal blog:

To better understand the state of viewable impressions, Google compiled data from its various display ad platforms, including its ubiquitous ad server DoubleClick. The study examined display ads that appeared in browsers on desktop and mobile devices, but did not include video or in-app ads. Here are five key findings from the research. Over half of online ad impressions aren’t visible. 56.1% of all display ad impressions never appeared on a screen, Google’s research found.

Let’s just quote here what a viewable ad is considered to be. As detailed in Google’s infographic (.pdf), summing the research up:

A display ad is considered viewable when 50% of an ad’s pixels are in view on the screen for a minimum as defined by the of one second, Media Rating Council.

Are media sellers going to give this information to their clients? Are they going to charge only for “viewed” ads (according to the above definition)? Seems like a potential big loss of revenues unless they step up their prices. How will they convince media buyers to swallow this price increase? By touting better performance only? Logically, “Viewed ads” should show better click-through rates and as a result motivate advertisers to spend more on these display ads. Is this a way for Google to boost ad spendings in the long run for its own ad network?

So many questions.