Understanding Google Analytics Assisted Conversions Data Discrepancies

Nico Brooks

August 31, 2016

Understanding Google Analytics Assisted Conversions Data Discrepancies

The Google Analytics assisted conversions report is very helpful for demonstrating which channels or sources indirectly influence conversions on a client’s site, but there are two somewhat confusing aspects to this report.

  1. The number of conversions shown by channel or source does not match other Google Analytics reports. Huh?
  2. The conversion numbers in the assisted conversions column sometimes exceeds the total number of conversions.  WTF?

Read on to learn why …

1. Why don’t last click conversion sources match other GA reports?

The assisted conversions report gives last click attribution to direct traffic. Other reports do not attribute conversions to direct traffic if the visitor has been to the site in the last 180 days, via another tracked source. In other words, if a visitor clicks on an AdWords ad and visits the site, then returns a day later by typing in the URL and completes a goal, the goal conversion will be attributed to AdWords in every report but the assisted conversions report. This means you will tend to see a lot more conversions attributed to direct traffic in the assisted conversions report, and fewer from other sources. Below is an example of the same goal being tracked in the assisted conversions report, and a regular report. Direct shows 9 last click conversions, but only 4 in the regular report. The other 5 conversions are attributed to other sources in regular reporting.

Here is the assisted conversions report:

Assisted conversions by channel

And here is a regular report of the same conversion by channel:

conv-by-channel

So, if you want to be able to tell a client how much credit a source should be given for assisted conversions in addition to the goal conversion numbers you get from regular reports, you need to correct the assisted conversions report to account for the different method of last click attribution. For example, in the reports above, Referrals are credited with one conversion in the regular report, but zero last click and 3 assists in the assisted conversions report. Here’s what the actual conversion paths looked like, more or less:

  • direct > referral > direct > goal conversion
  • direct > referral > organic > goal conversion
  • referral > direct > organic > direct > goal conversion

In this scenario, you have already counted the first conversion in your regular reporting, so it should be subtracted from the assist total.

Generally speaking, here’s the math: assisted conversions – (regular goal conversions – last click conversions) = true assisted conversions (e.g. conversions you haven’t already taken credit for).

2. And why can there be more assisted conversions than your conversion total?

A source is given credit for an assist whether it is the first click, second click, third click, etc. In other words, if a user visits a site 10 times then converts, the first nine sources are given credit for assists. But, to make matters even more confusing, a given source doesn’t receive assist credit more than once for the same conversion. Below is the multi-channel funnel report for the same client and goal as above. Notice that four referral visits preceeded conversions, but two of them were for the same conversion, so the assisted conversions report only gives referrals credits for 3 assists. Since one of those assists was followed by a direct click, we really shouldn’t be counting that one as an assist either, per above. Good lord.

mcf

You may be asking yourself, “if multiple sources can get assist credit for the same conversion, won’t that create an inflated view of the impact of marketing channels and sources?” That’s a good question. On the one hand, the assisted conversions report does help tell the story that multiple touchpoints are often involved in a purchase decision, but on the other hand it means that assists are worth an indeterminate and variable amount less than last click conversions, since a variable and indeterminate number of sources can share credit for the same goal.

What you could do is switch from ‘Assisting Interaction Analysis’ to ‘First Interaction Analysis’ in the Assisted Conversions report. That will tell you which sources first drove a visitor to the site. Arguably, this is the most important influencer of goal conversions.

Now that you know all that, keep in mind that there are a million reasons why complex purchases won’t be attributed correctly in GA, including cross-domain tracking issues, multiple decision makers, multiple devices involved in a purchase decision, and offline purchases. But hey, at least now you understand GA reporting better than most Google support reps.