Attribution modelling

Attribution modelling is a rule or set of rules to determine how much credit should be given to each touch point a customer has had with your business before conversion. It is an important part of digital analytics, especially for paid traffic such as PPC.

Beyond last click

Let’s say you run a law firm in Glasgow. You set up PPC to target “law firm in Glasgow”. Potential clients do a search and find your advert. They have a browser around, leave your site and interact with other competitors. Eventually they search for your business by name in Google , click on an organic search result and fill in an enquiry form.

If looking at last click attribution, which is the default in Google Ads, the conversion rate for PPC is 0. However, this new potential client would never have heard of your business without PPC. Therefore, you need to look beyond the last click and see if there are other ways to more accurately assign each touch point value.

Google Smart Goals

For anyone just starting with PPC, my recommendation is Google Smart Goals, which works if you have over 500 clicks a month. According to Google: “Smart Goals use machine learning to examine dozens of signals about your website sessions to determine which of those are most likely to result in conversions. Each session is assigned a score, with the “best” sessions being translated into Smart Goals.”

Google bases this on the top 5% of Google Ads coming to your site. Once that threshold is set, Smart Goals applies it to all your website sessions, including visits from other channels. After this has been established in Google Analytics, they can be imported into your Google Ads account, and you can optimise your campaigns on a CPA (Cost Per Acquisition) basis.

Beyond the basics

If you are a bit more comfortable looking at different ways to attribute the value Google Ads has added to conversions, you can change this within your AdWords account under Tools > Conversions > then click on the individual Conversions’ settings. The main methods are Last click, First click, Lineal, Time decay and Position-based. Personally, I prefer the Time decay model, where more credit is attributed to clicks that occur closer to conversion. Find out more about each one of these here.

If you have enough data, Google will offer you the Data-driven attribution option, where Google uses your data to best assign credit. This requires at least 15,000 clicks and 600 conversions per goal within the last month. This is probably the most sophisticated and best way to attribute credit to your Google Ads, but is not available to everyone. Find out more about this attribution model here.