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Getting Started With Attribution - Which Model Do I Choose?

This is part of our "5x5" series, in which we share five tips per week over the course of five weeks. We will share must-have tips about AdWords Editor, account optimization, ad-writing best practices, and much more. Make sure to explore the full series.

Welcome to part three in the attribution series. In the first part, we discussed what attribution is and how it can be used to improve your AdWords account and ensure that AdWords is getting the credit it deserves. In part two, we took things a bit further and looked at the entire sales cycle/funnel and understood that the customer journey is not only complex, but the steps a user takes are measurable. 


Today, in part three of the series, we’re going to look at the default attribution models in Google Analytics, what exactly they’re used for, and how they help us make better digital marketing decisions.




What Good Is Attribution?


So now that we know that our customers usually take multiple paths to our websites before they convert. What good is that? How do we know which steps that a user takes are valuable, and how on earth do we go about assigning value to each step?


The good news is that both AdWords and Google Analytics provide us with standardized ways to assign value (models), as well as offering us the ability to build our own. The bad news is that because every business is different, there’s no one-size-fits-all model. IT’S UP TO EACH BUSINESS TO FIND AN ATTRIBUTION MODEL THAT WORKS FOR THEM. This means that it’s up to whoever is in charge of each marketing department to decide the value of each channel themselves. There’s an obvious moral hazard here in that if an organization has multiple marketing departments that are independent of each other, each is going to want to use a model that emphasizes the importance of THEIR department over the others. Fortunately, there is a solution, but that solution first involves everyone understanding the different models available. Once we understand the different models, only then can we understand how the newest, most accurate and most exciting model works. So let’s dig in.


The Default Models


Attribution models can get quite confusing, but if you ignore the advanced stuff, it’s actually quite simple. Let’s go through them one at a time. I’m going to leave out a couple of models in order to keep things simple.


The Last Interaction Model




The last interaction model is basically the model that many beginners think that their marketing is based on. So if you advertise on AdWords and you generate a sale directly after an AdWords click, you give AdWords all the credit. Even if the user visited your site 100 times before the conversion via an email or a social link. This is the simplest way to attribute your conversions and was the standard up until only a few years ago. The standard AdWords reports use this model by default, so when you look at your campaign reports in AdWords, you’re looking at a last interaction model. It’s worth noting that Google Analytics DOES NOT REPORT BY DEFAULT using this model. Google Analytics default reports (all the reports you view day to day outside of the attribution reports) are actually based on a last NON-DIRECT click basis. More on that later though.


This model is, in my opinion, the least useful as it only gives credit to the most recent source of traffic and as such, is only really useful when attributing conversions where the customer generally purchases immediately after landing on your site (impulse purchase items).


The Last Non-Direct Model




The Last Non-Direct Click attribution model is the model you use when you believe that direct visits (visitors who type your website address directly into the address bar) have already been converted by another channel. This model is particularly useful when you want to filter out those people who you believe are already convinced and revert the attributed conversion back to the previous source.


The Last AdWords Click Model




The last AdWords Click attribution model basically gives all the credit to the MOST RECENT AdWords click. This is different from the last Interaction model and is useful for when you want to give all the credit to AdWords.


The First Interaction Model




The First Interaction Model basically assigns all credit to the first channel/source that the customer had an interaction with. If you run an AdWords campaign and the user clicks an ad, then considers their purchase overnight and returns the next day by typing your brand name into a Google search and clicking your organic listing, by default, organic gets all the credit. That’s hardly fair, is it?


This model lets you assign all the credit to the AdWords ad in this scenario. This is my favourite (of course) and gives a really great indication as to whether or not you should be disabling that campaign or keyword that looks, on the surface, to be performing badly. I’ll be doing a full post on this one so stay tuned for that!


The Liner Attribution Model




 By now you must be thinking, why not just assign credit to all steps in the conversion process equally? Well, with the linear attribution model, you can do exactly that. This may seem like the fairest way to dish out the credit but as I’ll demonstrate later, this is usually a bad idea. However, some teams might want to go with this option and at the very least it’s worth seeing how things look with an even view applied.


Position Based Model(s)





The position based model, up until this month, was the best of all worlds. IT HAS NOTHING TO DO WITH POSITION IN SEARCH RESULTS OR IN THE ADWORDS AUCTION. It allows you to assign a percentage of the credit to each step in the conversion process based upon how YOU think it should be applied. There are many creative and exotic ways to apply this model and some businesses spend/spent a lot of time fine tuning this to get it right. There’s even versions of this in the gallery that you can import based on the industry recognized best model available, the one by legendary Avinash Kaushik


Where to From Here?


There is one more model that Google has JUST MADE AVAILABLE this month and it’s slowly moving out of beta. This is the holy grail of attribution models and it takes away most of the confusion that the above models seem to generate. We’ll cover that in a lot more detail in the next part of this series.






For now though, explore the existing attribution models in your own account and see how each of them compare for your business. They’re available to everyone who tracks conversions in AdWords or GA and I think the results might surprise you. The traffic you thought was worthless might just be holding your entire business together! Join me tomorrow where we’ll explore automating the position based model with data driven attribution.

about Dave Davis

Skydiving and travel obsessed. Director of digital marketing agency Redfly, based in Dublin, Ireland. An marketing agency that specializes in AdWords management, Google Analytics and Google Tag Manager.