Cross-Channel Conversion Analysis: The Death Of Last Click Attribution

Conversion Attribution has become a big topic over the past few years. This is due to the growing acknowledgement that the typical user journey to conversion is often much more complex than simply clicking on an ad and converting. Most conversions happen after multiple visits to the site, with each visit representing a point in a larger progression called a conversion funnel.


Avinash funnel model (no KPIs)


Each of the three steps in this sequence may involve multiple visits from a number of different channels. Digital marketers who seek a more nuanced and complete understanding of the value of each of their acquisition channels are adapting a more holistic approach to attribution—focusing less and less on performance data in isolation.


Last Click Attribution Is Dead!


Last Click Attribution means only giving credit to the last acquisition source in the conversion funnel. Take a look at your Multi-channel funnel report in Google Analytics. Does it look anything like this?


(Blue = Paid Search , Yellow = Direct, Pink = Referral)
Channel overlap

If so, you have an attribution problem. As you can see, there is a huge amount of overlap across channels. Paid search traffic is overlapping significantly with Direct and Referral. Given this, it’s impossible to accurately assess the value of any of these three channels in isolation.


  • Last click analysis of PPC will undervalue the channel because of it’s role in driving direct and referral conversions.
  • Last click analysis of Direct or Referral conversions will overvalue the channels because many conversions originated via PPC.


Use Assist Conversion Value report to understand true value of campaigns


This report will give you a comprehensive look at the amount of revenue that was generated indirectly from your AdWords campaigns. You should take this report seriously if your attribution picture looks anything like the above graph. You may be astounded by the degree to which AdWords is helping to drive conversions via other channels.


Setting Your Conversion Windows


Both AdWords and Analytics give you the ability to customize the length of time during which Google will attribute your conversions to an original source. The maximum is ninety days, which is usually long enough for most businesses. Advertisers with extremely long sales cycles often create custom attribution models using a combination of Analytics data and personal data collected from users who sign up for a mailing list, fill out a contact form, request a catalog, etc.


Conversion Window customization


You’ll want to set your attribution window based on your own unique sales cycle.


Using Attribution Modeling Reports in Google Analytics


One new feature GA has provided to address this issue is the “Attribution Model Comparison Tool”. Essentially, it gives users the ability to look at their cross-channel conversion performance from a number of different perspectives and easily compare different models:
Attribution Model Comparison Tool


This image compares three different attribution views against each other: first click vs. last click vs. time decay. Time decay is one of a number of default options (you can customize your own) that gives you a more nuanced view than the more binary first and last click views. Time Decay weights the value of each channel in the funnel sequence, giving more credit by recency.




  • Last click attribution is only tells part of the story and should be avoided as the basis for assessing the value of your advertising channels
  • You can use Google Analytics reports to gain a much more detailed understanding of how your channels work together to drive conversions
  • Use cross-channel findings to take action by factoring in the real value of channels into your strategies, tactics, and optimizations