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Google Ads, PPC, PPC reporting, SEM

Which Google AdWords Attribution Model Should You Use?

4 October 2017

In order to maximize your AdWords budget, you need to determine which campaigns, keywords and ads get credit for your conversions. Enter AdWords Attribution. PPC Specialist John Horn provides insight into the best attribution model to use and why, and provides step-by-step instructions to set your account to your chosen method.

Determining Proper Credit For Conversions

Is your Google AdWords “Branded” campaign delivering your lowest cost per conversion?

If you’re like most advertisers, that’s what is happening. And it makes sense, because the people clicking your “Branded” campaign’s ads are already specifically looking for your company and are therefore far likelier to convert than people just generally searching the internet.

But . . . how many of your new customers knew to search for your brand name because they had previously clicked one of your non-branded ads earlier in their search process? Probably many more than you think. So if your “Branded” campaign is claiming 100% credit for those customers, it’s like a diva wide receiver claiming total credit for a catch. Never forget: no quarterback, no catch.

Here’s how to make sure each campaign on your “team” is getting the proper credit for the conversions you’re receiving.

What Does Attribution Modeling Mean?

To quote Google, “An attribution model is the rule, or set of rules, that determines how credit for sales and conversions is assigned to touchpoints in conversion paths.”

In other words, the attribution model you use for your PPC advertising dictates which campaigns, ad groups, keywords, ads, etc. get credit for your conversions.

Attribution modeling has always been important because your prospects frequently engage with your business via a broad range of channels before ultimately converting — and you need to understand how much value each channel deserves. I addressed the issue of properly tracking assisted and direct conversions in another blog post earlier this year.

Now attribution modeling is more important than ever because so many people are using their smartphones for initial research and then making purchases using a secondary device (e.g. tablet, laptop, desktop).

What Attribution Models Does Google AdWords Use?

Google AdWords offers six attribution models.

Last click: The last click gets all the credit for the conversion. If a customer clicks two of your ads, AdWords will credit the conversion to the second ad (and the associated keyword, campaign, etc.).

First click: The first click gets all the credit for the conversion. If a customer clicks two of your ads, AdWords will credit the conversion to the first ad (and the associated keyword, campaign, etc.).

Linear: Credit for the conversion gets distributed equally to every single click the customer made before converting.

Time decay: Every click gets some credit, but the closer the click is in the journey to the final conversion, the more credit it gets. If a customer clicks today, and then again a week from today and converts that day, the click today will get some credit for the conversion but the click a week from now will get a lot more credit.

Position-based: If there are more than two clicks in the journey, the first and last clicks each receive 40% of the credit for the conversion and the intervening click(s) get the remaining 20%, spread out evenly.

Data-driven: Google looks at thousands of signals to distribute credit for the conversion based upon its algorithmic understanding of how important each click was to the final conversion. This method is only available for accounts with a lot of data. Google doesn’t specify how much data you need to have, but in our experience you need to have tens of thousands of clicks per month.

Which Google AdWords Attribution Model Should You Use?

Last-click attribution has been the default attribution method for the advertising world for many years, so there is a pretty good chance that’s what you’re currently using in your account.

However, last-click attribution is generally NOT the best attribution model to use.

When available, we recommend data-driven attribution as the best model. Google’s algorithms analyze thousands of signals, way too many for us mere mortals to assess, to identify how much impact each click had on the final conversion.

Most accounts don’t have enough data to use data-driven attribution, so usually the next-best model is time decay attribution.

Why time decay? Unlike first click and last click, it assigns at least some conversion value to every click in the conversion journey. Unlike linear, it recognizes that not every click in the journey is exactly the same. Time decay assumes that the closer a click was to the time of the conversion, the more impact the click had on driving the person to convert, which is different than the assumption that position-based makes.

How Do You Change The Attribution Method In Google AdWords?

It’s actually very easy. You will need to tweak each conversion action in the account.

  1. Log in to your Google AdWords account
  2. Click Tools (in the menu at the top)
  3. Click Conversions
  4. Click the name of the first active conversion action
  5. Click Edit settings
  6. Click the box called Attribution model
  7. Select the attribution model you would like to use from the drop-down menu (if you don’t see data-driven as an option, then it’s not an option to use that method in your account)
  8. Click Done
  9. Click Save
  10. Click Done
  11. Repeat for each active conversion action in your account

Preview How A New Attribution Model Will Impact Your Account

Google has a handy tool within your AdWords account that will show you how your conversion data would have been reported depending on what attribution model you used.

  1. Log in to your Google AdWords account
  2. Click Tools (in the menu at the top)
  3. Click Attribution
  4. Click Attribution Modeling (in the menu on the left)
  5. Use the columns to compare different attribution models against each other and see the difference between your campaign CPAs and CVRs

Better Attribution = Better ROI

Why worry about what attribution model you use?

Using a more accurate attribution model helps you improve your Return On Investment.

If you scale back ad spend on broad keywords that don’t seem to be driving conversions because you’re using a last-click attribution model, and those keywords actually are driving the initial awareness that turns into a conversion through a Branded ad, you are going to limit how much money you can make.

If you reduce your bids on mobile because it looks like your cost per conversion from desktop is way better, but those desktop conversions are actually coming from people who found you on their phones, you’re going to lose lots of conversions.

A smart attribution model means a smart allocation of your ad dollars.

Go forth and conquer AdWords attribution!



John Horn is Director of Digital Performance at StubGroup Advertising, a Premier Google Partner ranked in the top 3% of all Google Partners worldwide. When he’s not writing books, teaching 10,000+ students online about AdWords, or playing foosball, John is leading his expert team of pay-per-click specialists in a never-ending quest to help StubGroup’s clients achieve their business and advertising goals via PPC. Connect with John at Twitter or LinkedIn.