What facebook's attribution window changes mean for marketers

Lately we’ve had a lot of conversations both internally and with our clients about the big topic on everyone’s mind: Facebook’s changes to the 28 day attribution window. With attribution driving so much of the digital conversation – and the way money is allocated – and Facebook being such a huge part of today’s media spend, this is a big deal.

Facebook has flip-flopped on the issue in the past, but as of today has removed the 28-day attribution window in favour of its 7-day attribution window. While this was previously available to advertisers, it was not the auto-selected attribution window during campaign

What is the Facebook 28 day attribution window?
Basically, attribution works by tracking what ads people have seen and assigning a value to those ads in the form of conversions. It helps us to know what ads someone saw before they purchased something — in effect, letting us know more about what happens and why.

But 28 days is a long time, particularly in the world of digital advertising. Whether or not that ad still impacted someone (and what the scale of this impact was, especially in an omni-channel funnel) is up for debate or interpretation. We tend to think advertising will influence during this period, but most media planners will tell you it depends on the category, adstock and messaging for each ad served.

Why are they changing it?
Facebook have changed the lookback window to 7 days. There are a couple of reasons they would do this:

• To make their own system more robust for other parties (some people are querying the lookback windows)
• To solve issues coming around long lookback windows (Apple’s privacy changes will hurt here)

The primary reason Facebook has given, though, is changes to digital privacy regulation. It seems like they’re trying to stop their own systems being compromised by hardware changes (Apple, Android) and regulatory changes (ACCC in Australia and the general push to digital privacy).

What would it mean for advertisers?
Firstly, most advertisers probably should take a 28 day lookback window with a grain of salt. In digital advertising social typically has an adstock of around 3 to 4 weeks depending on category (thanks to our friends at Mutiny for this data), so as you push things further out the data is likely to be less reliable.

Broadly, though, it will mean Facebook claims less conversions by default. If that happens, you might see the ROAS on your Facebook ads drop. That’s no cause for alarm — nothing has fundamentally changed. But the rules around what Facebook can ‘claim’ have, which is why your stock standard ads might see big drops.

What’s next and what should marketers do?
For marketers, you should be planning for a drop in ROAS or use this as an opportunity to build your own models to understand conversions. Typically, we advise clients not to look just at lookback windows, but to understand the relationship between ad spend and return over time across every channel (TV, social, search… everything!).

You should also use this to think about the very real limitations that are coming into the advertising ecosystem. As digital privacy ramps up, most conventional attribution models will be hurt or damaged in their ability to track results. Businesses need to rethink how they report success for a post-privacy world — and at Edge, that’s what we’re focused on helping our clients navigate next.

Of course, if you’re already use 1 or 7-day attribution windows, this will mean no changes to your current campaigns (yay)!

Image credit: @austindistel