There are more ways than ever to track and measure where your audience is coming from and how they are converting. However, are you tracking all performance fairly? In this post, we’ll discuss the recently introduced AdWords attribution models and how you can give the right amount of credit to each ad, click or keyword that led to a conversion.

With all the information available to consumers these days, it goes without saying that many will usually visit your site more than once, and will undoubtedly click more than one of your ads before they convert. How do you know which of your marketing tactics are working?

Image of AdWords attribution

We will talk about building and applying attribution models so you can give credit, and know how much credit to give, to each click utilizing the following models:

  • Last click
  • First click
  • Linear
  • Time-decay
  • Position based
  • Data-driven

Last Click

It is safe to say that a majority of advertisers are most familiar with the “Last Click” model in AdWords, and probably already use this model without even realizing it. Using “Last Click” gives all the credit to the last clicked ad and corresponding keyword that led to a conversion.

For all my sports buffs out there, it is basically saying it doesn’t matter who passed the ball. He who scored the point gets all the credit.

The benefit is that it is the easiest model to apply, however, you might be ignoring all of the other clicks your customer has made along the way. Using a more integrated attribution model will not only allow you to fit a better model to business, but will also assist you in reaching customers earlier in the conversion path and improve your bidding strategy.

First Click

If last click goes to the very last click, then first click is the exact opposite. First click attribution gives all the credit to the first clicked ad and corresponding keyword. Going back to the sports metaphor, whoever started the play, gets all the credit.


If first and last click models are too finite for your business, you might consider linear attribution. In this model, all clicks that lead to the conversion are given the same amount of credit.

Liner attribution allows for a team orientated model. All who played in the game get equal credit for the win. For example, if when you reviewed a linear attribution model and 30% of the middle of the funnel converts, you should consider building a +30% revenue into your model for assisted conversions.

Time Decay

Time decay offers a unique perspective, especially if your business has a longer conversion cycle. Time decay allows a weighted attribution, meaning clicks that happened closer to the conversion are given more weight than clicks that happened further away from the conversion.

AdWords has a 7-day half-life built into this model. If a click happens 8 days before a conversion, it is given half the credit as a click would receive if it happened the day before a conversion.


Position-based attribution does not mean the average position of an ad, but rather the position of click on a timeline. As an example, the first and last click ads and corresponding keywords are both given 40% credit, while clicks that happened in between the conversion path window are given 20%.


While this model is still in beta, it is worth mentioning. Data-driven attribution models automatically give conversion credit based on past data performance. If you have a new account or don’t have a ton of traffic, this model may not be available to you yet.


Using these attribution models will help shed light and identify if certain keywords, ad groups or campaigns are contributing to overall revenue even though they may not be bringing in direct conversions.