In a series of blog posts I’ll go through the most common online display marketing metrics. The aim of these posts is to give anyone who is new to the area a basic understanding of which metrics are used and how and when they are relevant. In this second post I’ll continue with some metrics that are common when buying display ads programmatically:
Although reach more or less is considered to be one of the basic measures, it has exploded in importance since the introduction of programmatic buying.
Reach is the number of browsers that have been exposed to an ad. Compared to impressions (which is the number of times an ad has been shown) in reach each browser is only counted once. Reach is not the same as number of individuals that have seen an ad. Any one person can (and most likely will) use several browsers (Chrome, Firefox, Safari, IE) on several devices (smartphone, tablet, work-PC, home-PC etc.) and will therefore be counted more than once when measuring reach.
At the early days of banners, purchases of online display used to be treated in the same way as purchasing display ads in newspapers. You paid for e.g. 1 million views of your ad and that was (hopefully) what you got. Adserving was introduced to handle this, but you still had no idea if the spread of that between different site visitors was uneven. Site owners then started capping the frequency of ads so that one visitor only was shown the ad a limited number of times. By doing this they increased the reach for the advertisers message and thereby could deliver a higher reach for more advertisers at the same time.
With programmatic the same type of frequency capping is done, but now on a global level. By global level I mean that the number of times an ad is shown to a specific browser, regardless of site, is limited and set by adjusting the frequency variable in a DSP.
As stated above, frequency settings are used to even out the number of exposures one ad has per browser. Used correctly this will both minimize the ad fatigue obtained if an ad is shown too often as well as ensure that the ad has a higher reach.
Frequency rules are possible to set on specific levels for different time intervals. The optimal frequency settings on an hourly, daily, weekly and so forth, basis depend on budget, available inventory for the chosen target group and what the goal of the campaign is (reach, CTR etc.).
One of the hot topics in display marketing is viewability (also sometimes referred to as in-screen). This is a metric that shows if the ad has been visible on the users screen. The proper IAB definition of viewability is that at least 50% of the ad has been visible for at least one second.
Viewability is often displayed as a percentage of impressions (e.g. 80% of the impressions). Viewability and viewable impressions (the number of impressions that were viewable) are two important metrics when comparing different placements.
Combining this with cost data (vCPM = viewable CPM) will give you a better view on how to optimize your spend than just using eCPM. Quite often one can see that sites that have a very low eCPM can be quite expensive when adding the Viewability metric to the calculation.
In the table to the right I’ve compared 20 sites in Norway and it becomes clear that a cost optimization based on vCPM instead eCPM would give a different site mix and much higher effect.
Please don’t hesitate to comment if you agree, disagree or have any questions about the metrics. In my next post I’ll pause from metrics and take a look at browser profiles.