If you’re selling something online then Facebook’s and Google’s Ad platforms are great tools to generate revenue at scale from targeted, personalised ads. In doing so, each platform tracks online sales with a piece of code which you install on your website. That piece of code can track a user seeing an ad, on Facebook, for example, clicking through to your website and then making a purchase. This way each platform can attribute, basically award itself, for the revenue that it has driven. This is critical when measuring return on ad spend or ROAS for short.
So, if each platform attributes the sales it generates, then what is an attribution window, why is it needed and how can it dramatically change the effect of your advertising?
Put simply, an attribution window is the amount of time you allow between a user seeing an ad to then making a purchase. Let’s break it down, firstly with Facebook:
Facebook’s Attribution Windows
Facebook operates two different attribution windows within its reports, click and view, on a 1-day, 7-day or 28-day time window. You can choose to use both click and view AND multiple different windows, these are the options you can select in Facebook’s ads manager.
So let’s run through what this means in a real-world example, starting with the view attribution window.
Let’s say John is browsing his Facebook news feed and he comes across an ad for a laptop, he stops scrolling, reads the description and looks at the image for a few seconds. He then continues scrolling through his news feed. John has just registered as a single impression for that ad, considering he viewed the whole ad for more than 1 second.
6 days later John’s current laptop dies and he needs a new one. He remembers the ad he saw and decides to go to that retailer’s website and purchase the laptop. John’s decision to buy that specific laptop from that retailer was certainly influenced by that Facebook ad so Facebook deserves to take credit for the sale it drove. This is attribution.
Now, if you ware measuring the revenue driven by Facebook ads on a 1-day view window this would record all revenue driven after 1 day of a user seeing your ad. With this attribution window, you would be excluding the revenue Facebook generated from John’s laptop purchase and therefore the overall revenue which Facebook drove would be lower. If you expanded this attribution to a 7-day view, then John’s purchase would be included in the reported revenue driven by Facebook and so forth overall revenue-driven would be higher.
The exact same logic applies to the click attribution window, the only difference is that this attributes all revenue driven by users who have clicked through an ad rather than just viewed. Revenue recorded using click attribution will typically be higher than revenue recorded using the view attribution as there is generally more intent to buy from a user who clicks than a user who just views an ad.
So, what type of attribution should you use, view or click and what time window should you use?
Unfortunately, there is no, ‘one-size-fits-all’ answer for this as different products and different markets will all have varying customer journey lengths. For example, the customer journey and decision time to buy a pair of £2 socks is probably extremely short, a matter of minutes. Whereas the customer journey and decision time to buy a high-value car will be much longer, most likely days, weeks or even months. Therefore the attribution window that you choose to use needs to be in-line with your average customer journey and decision time.
However, if you are running a standard e-commerce store I would recommend using a 1-day click attribution window only for optimization purposes. Using this short and very restricted attribution window will mean that your reported revenue performance and ROI is lower but it allows you to make optimisation decisions within 1 day.
If you chose to use a 7 day click attribution window then you could only make a fair judgment on ad activity that you ran 7 days ago. By which time, you could have optimised your budget to be spent in a more effective way and maximized returns. This is why it is best to be very harsh on your performance using a 1 day click attribution window to quickly discover what is working and what is not and to act on that calculated optimisation.
Google’s Attribution Windows
Google’s attribution windows act in very much the same way as Facebook’s and the logic behind them is identical. However, Google defines the ‘attribution window’ as ‘conversion window’ and asks you to set your preferred conversion window for both view and click based on the conversion event.
Basically, this means that if you have a conversion event script on your website which is linked to Google ads, you have to set your preferred time window in days on both the view and click conversion window on that conversion event and once set, your reporting will be based on those set conversion windows.
Google allows you to customize the time window to any number of days up to 30 on view and any number of days up to 90 on click.
So to sum up, an attribution window or conversion window is simply the amount of time you allow between a user seeing an ad and making a purchase, in order to then attribute that purchase accordingly the ad’s driven revenue.
Whilst its a good idea to measure ad performance within a limited 1-day click window for optimisation, if you are measuring your overall advertising performance within a too restricted conversion window then you could be missing out on reporting thousands of pounds worth of driven revenue.