An essential part of any Google Ads campaign is conversion tracking, so that an advertiser can tell which keywords and ads are working best. However, a customer may make multiple searches and interact with multiple ads from the same advertiser before completing the desired conversion, so the use of attribution models let the advertiser choose how much credit each click gets for the conversion.
Using the various attribution models in Google Ads allow advertisers to attribute the credit to the customer’s first click, last click, or a combination of multiple clicks, which can mean that conversion numbers can show decimals (or part conversions) for a selected time period. These attribution models can give advertisers a better understanding of how their keywords and ads perform and can help them optimise across the user’s conversion path.
Most advertisers measure the success of their online advertising on a “last click” basis. This means they give all the credit for a conversion to the last-clicked ad and corresponding keyword. However, this ignores the other clicks customers may have made along the way through the same Google Ads account before converting and so the various attribution models give advertisers more control over how much credit each ad and keyword gets for these conversions.
Google Ads offers several attribution models (similar to those used in Google Analytics), which are as follows:
Last click: This is the traditional conversion setting and gives all credit for the conversion to the last-clicked ad and corresponding keyword.
First click: Gives all credit for the conversion to the first-clicked ad and corresponding keyword.
Linear: Distributes the credit for the conversion equally across all clicks on the path.
Time decay: Gives more credit to clicks that happened closer in time to the conversion. Credit is distributed using a 7-day half-life. In other words, a click 8 days before a conversion gets half as much credit as a click 1 day before a conversion.
Position-based: Gives 40% of credit to both the first- and last-clicked ads and corresponding keyword, with the remaining 20% spread out across the other clicks on the path.
Once an advertiser sets up conversions in Google Ads, they can choose the setting to decide how to attribute conversions for each conversion action. This setting affects how conversions are counted in the “Conversions” column. For example, if you choose “First click” as your attribution model, conversions will be credited to the first ad customers clicked before completing a conversion. In your reports, the conversions would count in the campaigns, ad groups, ads, and keywords associated with the first-clicked ad.
The attribution model you choose only affects the conversion action to which it’s applied, and only affects your Search Network and Shopping data, whereas Display Network conversions and app and phone call conversions will still be attributed to the last click.
The setting also affects any bid strategies that use the data in the “Conversions” column. This means that if you use an automated bid strategy that optimises for conversions, such as Target CPA, Enhanced cost-per-click (ECPC), or Target ROAS, the attribution model you select will affect how your bids are optimized. If you use manual bidding strategies, you can change your attribution model to help you set your bids.
If you’d like to know more about conversion attribution models and how they might affect your conversion data, please contact us for details.