qCPM and Why Not All Impressions Are Equal

April 20, 2021

If the goal of your digital campaign is an online action, such as a sale, registration or download, there are a lot of great performance indicators that can be used to measure effectiveness across channels, including conversion rates and cost per action. If you can assign a value to those actions, you can drill deeper into return on investment and more directly translate media investment into business results by measuring return on ad spend.

But what about when online activity after ad exposure isn’t particularly relevant to your objectives? What if you are looking for awareness and delivering a straight forward message that’s easily captured without a website visit? What if you are just brand building? In those instances, focusing on delivery metrics, such as viewability, media costs, total impressions and good ol’ reach and frequency will usually correlate closest with ad effectiveness.

All impressions aren’t created equal, though. It’s hard to compare a video impression to a banner impression, for example, since both their costs and effectiveness are different. Even within banners, there can be a huge variance between how effective different placements and sizes are that isn’t captured in just a total number of impressions. That’s where qCPM or quality based impression measurement can help.

The qCPM Model

By defining what a high quality impression actually is we can make more fair comparisons in reporting while also ensuring we’re focusing on premium inventory. Quality CPM is an arbitrary scoring framework that can mean different things to different groups, but should be consistent campaign over campaign to establish benchmarks. That framework could consider a variety of indicators, from viewability to ad size to whether the ads appeared in a brand safe environment.

As a starting point, viewability is a great foundation for a qCPM formula. A $4 CPM at 50% viewability and a $6 CPM at a 75% viewability both work out to an $8 viewable CPM (vCPM), so by measuring viewability we can already tell a richer story than just looking at CPM alone.

What about ad sizes, though? Is that tiny mobile banner at the bottom of an app as impactful as a tall block that fills the screen on a mobile device? The first is 16K pixels and the second is 180K pixels, meaning it’s taking up over 11 times more real estate. You want more of that, right? By assigning a weighting system in your qCPM model, you can score the tall block banner impressions higher and the mobile banner impressions lower, shifting the composition of your ad buy towards higher impact ad units that may cost more, but are also more likely to be effective.

Other factors to consider include brand safety, ensuring ads are appearing in reputable places not only in the form of avoiding inflammatory or damaging content, but also aligning brands with websites and apps they’d actually like to appear on, rather than some of the bottom barrel inventory that starts to appear when programmatic campaigns are left unchecked.

Working towards more robust models to measure awareness can take a lot of time to get right, but once established, it can help tell a more meaningful story about ad effectiveness that avoids the distraction of vanity metrics.