How does… Google AdWords’ new attribution model work?

Each week, we ask some of the industry's most knowledgable boffins to break down industry jargon to help you through those confusing meetings and indecipherable conferences. This week, GMG Digital's John Vlasakakis explains how Google AdWords' new attribution model works.

Google AdWords is changing. Here is what you need to know.

There have been rumblings recently that tech giant Google would stop supporting last click attribution in 2018, meaning advertisers will now opt into one of the other attribution models the company currently offers.

There are a few things current and potential advertisers should know before the new system rolls out later this year.

What is an attribution model?

Google themselves define an attribution model as a “rule, or set of rules, that determines how credit for sales and conversions is assigned to touchpoints in conversion paths.”

As it stands, the default model Google employs is last-click attribution, which assigns the final click prior to the conversion event with one hundred percent of the credit. In the complex maze of online advertising, this can be a reductive and incomplete method of determining how and why consumers make their way to online purchases.

What you should know

There are of couple of things you should remember about attribution in light of Google’s plans.

Firstly, when you change your attribution model, it isn’t giong to affect the performance of your account. The other available models will simply offer you a more thorough understanding on the data you already have. It is important to keep everyone involved in your organisation of the incoming changes to avoid misunderstandings regarding the new reports.

Secondly, the new model won’t interfere with your account. You will be able to see what all the various models tell you about your data with compromising your original reporting.

It is thought that the data-driven attribution model will become Google’s default option, with advertisers than being allowed to choose other models at their leisure. Additionally, it has been suggested Google Analytics will offer a function assigning different weight and credit to things like paid search, paid social, email marketing and direct channels.

What are the different options?

There are five different attribution models advertisers will be offered in AdWords:

  • First-click model – as the name suggests, the first touch point is given one hundred percent of the credit for a purchase. This option would appeal to advertisers concerned with new customers, as it gathers information on persons who have shown an interest in a product, and can be marketed to further down the line, through methods such as email lists and targeted advertising.
  • Time decay model – this model favours the touch points closes to the final conversion; the clicks a customer makes right before making a purchase are given extra weight. In this sense, it provides a similar understanding of customer behaviour to last-click attribution and so advertisers content with the current situation may favour this.
  • Position-based model – this would assign forty percent of credit to both the first and last interaction before conversion and the remaining twenty percent to all other clicks. This provides considerable weight to the beginning of a customers journey and their final, definitive decision, whilst acknowledging that keywords along the way contributed without being as essential.
  • Linear Model – this models assigns equal weighting to every touch point involved in a conversion. This will allow advertisers to distribute credit evenly to all the keywords in the customers journey towards a purchase, and is useful in understanding low volume and long-tail phrases, which provide useful information that is often missed in last-click attribution.
  • Data-driven attribution model – the most complex attribution model and the one favoured by Google themselves. It provides analysis of each touch point and establishes where credit should be applied for each individual journey. In theory, this is a tailor-made service for advertisers, but Google decides what is important and not the individual companies, which may not be for everyone. It should also pointed out, this option isn’t available to everyone. In their own words: “DDA (data-driven attribution) is different from rules-based attribution models. It uses your account’s conversion data to calculate the actual contribution of each search ad click along the conversion path… The model observes what your customers do before converting, and what they do when they don’t convert, to measure what’s important. Using Google’s machine learning, the models continue to improve over time”.

There is plenty to think about as Google moves forward with this project. Hopefully, with last-click attribution’s impending demise, advertisers will be provided with diverse, complex and nuanced reporting on their data in a way they may not have seen before, which can only be a good thing. Time will tell.

John Vlasakakis is head of search and digital media at digital marketing agency GMG Digital.


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