A customer can interact with your marketing several times before becoming a customer.
They might first discover your business through an advertisement, return through a search result, read an email later, and finally purchase after another visit.
When that happens, a simple question becomes surprisingly important:
Which interaction should receive credit for the conversion?
First-click and last-click attribution are two straightforward ways of answering that question. They can produce very different views of campaign performance, even when they are based on the same customer journey.
Understanding the difference helps you interpret your reports properly and choose the model that fits the question you are trying to answer.
What is first-click attribution?
First-click attribution gives the conversion credit to the first tracked interaction in the customer’s journey.
Imagine someone discovers your business through a social media advertisement. They do not buy immediately. They return later through another channel and eventually make a purchase.
Under a first-click model, the original social campaign receives the credit.
This makes first-click attribution useful when you are interested in discovery and acquisition.
You can use it to understand which channels are introducing people to your business in the first place.
That can be particularly relevant for campaigns designed to reach new audiences.
What is last-click attribution?
Last-click attribution gives credit to the final qualifying interaction before the conversion.
Using the same customer journey, suppose the visitor eventually returns through an email and purchases.
The email receives the credit under a last-click model.
This makes last-click attribution useful when you want to understand what was immediately associated with the conversion.
It can be particularly helpful when evaluating campaigns designed to bring an already-interested prospect back to complete an action.
The same customer can produce different answers
This is where attribution becomes interesting.
The first interaction and the last interaction may both have played an important role.
The first introduced the customer.
The later interaction helped bring the customer back.
The final interaction preceded the purchase.
First-click attribution highlights the beginning of the journey.
Last-click attribution highlights the end.
Neither model changes what happened. They simply assign the credit differently.
That is why you should never look at an attribution report without knowing which model produced it.
When first-click attribution is useful
First-click attribution can be particularly useful when your marketing objective is customer acquisition.
Suppose you are testing several channels to discover which ones are bringing new prospects into your marketing system.
A source that consistently appears as the first interaction may be doing an important job even if it rarely appears as the final interaction before a purchase.
If you judged that source only by last-click conversions, you could underestimate its role.
First-click reporting gives you another way to see the acquisition side of your marketing.
When last-click attribution is useful
Last-click attribution can be useful when the immediate conversion action is your main concern.
For example, you may want to compare the campaigns that are consistently bringing prospects back to complete a purchase, registration, or enquiry.
A campaign that frequently appears immediately before the conversion may perform very well under a last-click model.
That does not necessarily mean it created the customer from scratch.
It tells you that the interaction was the final recorded step before the conversion.
That distinction is important.
Neither model tells the whole story
A customer journey can contain several meaningful interactions.
If you assign all the credit to the first interaction, you can overlook what happened later.
If you assign all the credit to the last interaction, you can overlook what brought the person into your marketing system.
This is the fundamental limitation of single-touch attribution.
It simplifies a multi-step journey into one credited interaction.
That simplicity can be useful. It can also hide useful information.
The right choice depends on what you are trying to learn.
What about multi-touch attribution?
Multi-touch attribution attempts to account for several interactions within the same journey.
Instead of assigning the entire conversion to one touchpoint, credit can be distributed across multiple interactions according to a chosen model.
There are several ways of doing this.
Some models divide credit evenly.
Others give greater weight to particular positions in the journey or to interactions closer to the conversion.
This can provide a richer view when customers regularly interact with several campaigns before converting.
It also introduces more assumptions into the analysis.
The more sophisticated the model, the more important it becomes to understand how it distributes credit.
Attribution is not causation
This is one of the most important things to remember.
If an interaction receives attribution for a conversion, that does not prove that the interaction alone caused the customer to buy.
Attribution is a method of assigning credit within a defined measurement system.
The customer may have seen an advertisement, spoken to someone, read reviews, visited the website several times and received an email before purchasing.
Your attribution model cannot capture every influence on a buying decision.
It gives you a consistent way to analyse the interactions that your tracking system can observe.
That makes attribution useful for comparison and decision-making, without making it a perfect explanation of human behaviour.
Attribution windows change the result
The period during which an interaction can receive credit also matters.
Consider someone who first visits through a campaign and purchases much later.
Whether that original interaction remains eligible for attribution depends on the rules being used.
A short attribution window may exclude it.
A longer window may include it.
This means two reports can analyse the same customer journey and produce different results simply because they use different windows.
When comparing reports, always check the attribution window as well as the attribution model.
Attribution should match the question
Instead of asking:
“Which attribution model is the correct one?”
ask:
“What am I trying to understand?”
If you are evaluating which channels introduce new prospects, first-click attribution can provide a useful perspective.
If you are examining what tends to precede conversions, last-click may be useful.
If your customers interact with several campaigns before purchasing, a multi-touch model may provide additional insight.
You may even use more than one model when analysing the same marketing system.
There is nothing contradictory about that.
Different views can answer different business questions.
Why this matters when comparing campaigns
Imagine two campaigns.
One frequently appears as the first interaction but rarely as the final interaction.
The other rarely introduces visitors but frequently appears immediately before a purchase.
Under first-click attribution, the first campaign may look stronger.
Under last-click attribution, the second may look stronger.
Neither report is necessarily wrong.
They are measuring different positions in the journey.
This is why changing the attribution model can change your campaign rankings without changing the underlying campaign activity.
The model has changed the way credit is allocated.
What you should check in an attribution report
Before drawing conclusions, look at:
- the attribution model being used;
- the attribution window;
- which interactions are eligible for credit;
- how returning visitors are handled;
- what counts as a conversion;
- and whether the tracking setup is capturing the relevant journey.
Without that context, an attribution figure can look more definitive than it really is.
Using attribution to make better decisions
Attribution becomes useful when it helps you make a decision.
You might use it to decide where to investigate further, which campaigns deserve more attention, which acquisition sources are introducing prospects, or which interactions tend to appear close to conversion.
It should help you ask better questions about your marketing.
It should not become a competition to find the one report that gives a campaign the highest credit.
The strongest analysis often comes from looking at the journey through more than one lens.
The bigger picture
First-click and last-click attribution are simple models, but they introduce an important idea:
The value of a marketing interaction depends partly on where it appears in the customer’s journey.
Once you understand that, attribution reports become easier to interpret.
You can see why different platforms may give different campaigns credit.
You can understand why changing the model changes the results.
And you can choose an approach based on what you are trying to learn rather than assuming that one model is universally correct.
For the broader relationship between tracking, conversions, and attribution, see Click Tracking & Attribution.
A tracking platform worth exploring
If you want to examine different attribution approaches within a dedicated tracking system, ClickMagick is worth exploring. Its current platform supports multiple attribution models, including first-click, last-click, linear, position-based, and time-decay approaches.