Advertisers have more and more types of online ad inventory than ever, and thanks to technologies like real-time bidding, increasingly sophisticated ways to buy them.

But for advertisers actually hoping their ads will reach consumers, there’s bad news.

According to a study by AdSafe Media, just half of all online ads meet the Making Measurement Make Sense (3MS) proposed viewability standard that calls for 50% of an ad to be visible for at least one second.

As my colleague Heather Taylor described earlier this month, one of the guiding principles behind 3MS is that the industry should move from measuing “‘served impressions’ to ‘viewable impressions’ to prevent the over-counting of impressions.”

This makes sense for advertisers, but AdSafe Media’s study, which looked at impressions served in the first half of the year, suggests that publishers, ad networks and ad exchanges could have problems living up to the standard.

Those problems could be particularly acute for the latter two groups. According to AdSafe Media, well under half (41.2% and 40.3%) of ads served by networks and exchanges met the proposed viewability standard, respectively. Ads sold directly by the publisher fared a bit better, but even for publisher-sold ads, advertisers may not be thrilled with the results: little more than a fifth of these ads (21.2%) remained in-view for 15 seconds.

When ad worlds collide

And it gets worse: in approximately 7% of cases, an advertiser had two ads on the same page. As Adweek’s Tim Peterson writes, “While doubling up an advertiser’s presence on the page could juice the likelihood of the brand’s paid media being seen…it ‘represents a pretty significant loss of value’ because the likelihood of a user converting drops for both.”

Assuming AdSafe Media’s findings are confirmed by others, it would seem that the industry has a big question to ask: why adopt a viewability standard that is apparently going to be very hard to meet?

While advertisers have a natural incentive to push for measurement metrics that ensure they’re not overpaying for what’s being delivered, barring some fundamental change in online ad units and how they’re positioned, it’s questionable as to whether those in business of selling ad inventory will be able to do much to change the viewability of the ads they sell.