Last-click attribution has been the default in affiliate marketing for as long as affiliate marketing has existed. The model is simple: the last partner to drive a tracked click before a purchase gets credited with the sale. It is easy to implement, easy to explain, and for a long time it felt like enough. For most programmes today, it is leaving a significant part of the picture in the dark.
This is not about blame. Last-click attribution became the industry standard for good reasons, and it still does certain things well. But as affiliate programmes have matured and partner mixes have become more sophisticated, with editorial content partners, comparison sites, influencer affiliates and loyalty platforms all operating alongside each other, the single-click attribution model has become an increasingly poor proxy for commercial contribution.
Partners who introduce customers to a brand, build consideration over weeks, or influence purchase decisions through editorial rather than promotional activity are being systematically undervalued. Partners who intercept customers at the final moment before purchase are being systematically overvalued. The result is a measurement framework that can quietly incentivise the wrong partner mix, often without anyone realising it.
What last-click actually captures
Last-click attribution measures one thing with precision: which partner was active in a customer’s browser at the point of purchase. What it does not capture, and genuinely cannot, is which partners were responsible for bringing that customer into the funnel, building their consideration of the brand, or creating the intent to purchase in the first place.
For a brand with a short consideration cycle, this distinction barely matters. For a brand with a longer one, luxury goods, considered premium purchases, high-involvement categories, the customer journey between first exposure and purchase typically involves multiple touchpoints over days or weeks. Last-click assigns all commercial credit to one of those touchpoints and zero credit to everything else.
What tends to get missed
Editorial content partners, lifestyle publishers, review sites, independent fashion and beauty writers, typically influence purchase decisions early in the journey. A considered piece of editorial introducing a skincare brand creates genuine commercial intent. It does not always capture the final click. Influencer affiliates with genuinely engaged audiences operate similarly. A creator whose content a customer follows regularly may drive the initial brand consideration, but the customer returns later, finds a cashback link through a browser extension, and completes the purchase. Last-click credits the cashback partner. The creator who did the commercial work does not appear in the data at all.
What tends to get over-credited
Browser extensions and cashback platforms are structurally advantaged by last-click attribution. They activate at the point of purchase, often triggering automatically when a customer is on a retailer’s checkout page. This means they regularly capture the final click on journeys generated entirely by other partners, or by the brand’s own marketing activity. Voucher code sites operate the same way: a customer who has already decided to buy searches for a discount code before completing their purchase. The voucher site gets the click and the commission. The channel that created the intent to purchase gets nothing.
None of this is a criticism of these partner types. They serve a genuine role. The issue is purely one of measurement: what last-click attributes to them, and what it attributes to others, does not always reflect who actually did the commercial work.
Attribution models worth considering
Moving away from last-click does not have to mean a wholesale overhaul of your programme. There are several approaches that produce a more complete picture.
First and last click combined is the simplest starting point. Track both the first and last click in any customer journey. This immediately surfaces which partners are consistently introducing customers versus which are consistently capturing final clicks. The data alone often changes how programmes weight their partner relationships.
Time-decay attribution distributes credit across all touchpoints in a customer journey, with more credit given to touchpoints closer to purchase. This still advantages last-click partners, but it acknowledges the contribution of earlier touchpoints rather than ignoring them entirely.
Position-based attribution assigns a fixed percentage of credit to the first touchpoint, a fixed percentage to the last, and distributes the remainder across the middle of the journey. This explicitly values both partner introduction and partner conversion, which is a much better fit for programmes with meaningful editorial content partnerships.
Incrementality testing is the most rigorous approach: testing whether partner activity is actually driving additional revenue that would not have occurred without that partner. This goes beyond attribution modelling into experimental measurement, but for significant affiliate investment, it provides the most defensible commercial case for partner value.
Where to start
If your affiliate programme runs on last-click attribution and you have not reviewed what that means for your partner mix, start by pulling your first and last click data side by side. Look at which partners consistently appear as first click but rarely as last click. These are your introduction partners, and they are likely undervalued relative to their actual commercial contribution. Look at which partners consistently appear as last click but rarely as first. These are your conversion capturers, and it is worth understanding how much of that conversion they are genuinely creating versus arriving at the end of a journey someone else started.
The goal is not to discredit any partner type. It is to build a measurement framework that reflects what is actually happening across the full customer journey, so that commission structures, partner investment and programme development decisions are made on an accurate commercial picture rather than a partial one.
If you are working through what that looks like for your programme, we are always happy to talk it through.
