In the context of digital marketing, the first interaction model is a method for attributing credit for a conversion to the first marketing channel or touchpoint that the customer interacted with. This model is also known as first-click attribution because it gives credit to the first channel or touchpoint in the customer journey.
For instance, let’s say a customer searches for a product on Google, clicks on an ad for the product, and lands on your website. The customer later returns to the website directly, without clicking on any ads, and makes a purchase. In this case, the ad click would be credited with the conversion under the first interaction model, even though the customer did not click on any ads after their initial visit.
The first interaction model is a simple and easy-to-understand attribution method and is often used as the default model in many digital marketing platforms, including Google Analytics.
However, it can be unfair to later-stage channels and touchpoints that may have played a significant role in the customer's journey.