Advertising Technology, Business

Viewable impression tracking and pitfalls.


Viewable impression tracking and pitfalls.: April 22, 2013 by Maciej Zawadziński Chief Executive Officer

Recently, online advertising seems inevitably moving towards ‘viewable’ impression model. A model, in which advertiser theoretically shall pay only for advertisements that were actually displayed to a user.

In this post I am going to explore a few technical aspects of tracking viewable impressions and explain why this model may not solve problems which lie at the origin of it.

CPM display advertising and origins of viewable impression.

Since early years of online display advertising, the most popular pricing model for selling online ads is banner impression buying and giving prices in CPM  (CPM = cost per mile, which means cost per 1000 impressions).

The problem with this model is that many ads are not seen by the user at all because they are displayed below the fold (for example in the middle or bottom area of the page where many of visitors do not scroll to), not to mention frauds of long-tail sites that come up with many tricks in order to cheat tracking impressions of many ads that could never be seen on the page.

With more and more inventory available on the market, increasing spent on the online advertising and growing number of ad technologies available, it is natural that advertisers want to find a way to pay only for the inventory that could bring value (and obviously ad impressions that are not displayed at all are not something that any advertiser would like to pay for).

A big hope is placed in so called viewable impression

Viewable impressions. What they are and how are ‘views’ measured by ad technology?

The idea behind viewable impression is pretty straightforward. Advertiser pays only for ads impressions that were actually seen by a user. Sounds simple, but the problem is much more complex when analysed from the technical perspective.

First of all, what does it mean that ad was seen? Usually this is assumed when at least 50% of the advertisements area was in user’s browser viewport for more than X seconds. So far, so good, but it gets interesting when measuring it with various technologies gives different results or when part of impressions are classified neither viewable nor non-viewable due to limitations of browser capabilities.

There is a good video from TraderTalk TV explaining technical issues around viewability and giving insight into current solutions that are used by ad technology vendors:

Key take-aways from this video are:

1) commonly used geometric method (calculating the relative position of the ad on the screen and determining if it’s in users viewport) is not cross-browser compatible (e.g. does not work on Webkit-based browsers) and could be easily cheated,

2) very effective seems to be a proprietary technology developed by Spider.io which measures rendering properties of the ad (taking advantage of the discovered fact that rendering frame rate and other parameters of elements actually visible in the browser window differ from those that are not visible).

Other companies on the market that deploy viewable impression technology besides Comscore and Spider.io include: AlentyDoubleVerify, Moat, Integral Ads  (formerly AdSafe), Meetrics, Onscroll, Telemetry, RealvuVizu and for sure many others.

Personally I doubt that any of above techniques will eventually become a standard as the variety of devices that users use to consume online content constantly grow and change (ranging from desktops/laptops, through smartphones, tablets, game consoles, smart TVs etc.) and will make both techniques not sustainable. Also, proprietary technology is hardly going to be adopted widely by all players on the market.

Effectiveness of ads – ‘noticeable’ impressions, user intent and others.

The main driver of pushing standard of viewable impression is to improve results of online campaigns.

Of course, besides ad viewability, there are several other factors that impact the effectiveness of ads that are usually taken into account by advertisers :

  • creative attractiveness, the more eye catching and interesting an ad is, the more likely that user is going to engage with it and/or remember it,
  • right targeting / audience buying, starting with simple context and geo targeting, through various user/site-centric researches, up to behavioural targeting, there is a plenty ways of increasing likelihood of displaying an ad in front of right users,
  • frequency, exposing a user to an ad with the right frequency could increase effectiveness of the ad (usually campaigns has set capping – maximum amount of impressions of single ad/campaign that single user is exposed to during specified period of time – e.g. one day).

All of above are nowadays relatively easy implemented with larger or smaller success in online advertising campaigns. However, there are a few other factors that can impact greatly the effects of the campaign, but are rather either omitted or are still in early stages of ad technology implementation:

  • ad noticeability, it depends on the placement position and its context – for example if your page is cluttered with content and ads, the likelihood of even noticing your advertisement is decreasing dramatically,
  • ad exposure time and forced frequency, right now in most ad networks/media buying tools you can set only capping (maximum number of times that a user is exposed to an ad), but potentially much more effective would be if you can optimise campaigns for certain amount of ad exposure time and/or minimum number of times that you want users to be exposed to a given ad,
  • user intent, combining standard audience targeting with intent of the user at the given time (e.g. am I researching given area, comparing offers, or I have an intent to buy right away) can be very powerful as you can serve the right ad content (and guessing by keyword  in SEM campaigns is not fully reflecting the user intent).

CPM vs CPV pricing.

Similar to financial markets, current CPM prices are reflecting the supply and demand for online ad inventory, including the fact that part of impressions are non-viewable.

Moving towards CPV, should theoretically result in better campaign performance for the same price paid by an advertiser. But that does not fit into a ‘free market’ model…

When the supply of impressions is cut (nobody want to buy non-viewable ones), we can expect that the CPV, after possibly a few months of destabilisation, will get to the level where advertiser pay around the same for similar campaign effects, but with only viewable impressions.

It does not sound that bad… but as the technology isn’t ideal (e.g. some of impressions couldn’t be determined to be viewable or not), this could lead to even higher prices for viewable impressions and as a result lower effectiveness of display campaigns.

Of course, current model where advertisers pay for ads that may not be always displayed isn’t ideal, but until we have an open standard for viewable ads in place that is cross-device compatible and reliable, i don’t think it could make any good.

Further reading:

Photo credit: x-ray delta one