First Click, Last Click, or First Wins: Choosing an Affiliate Attribution Model
Two partners touch the same sale — who gets paid? What each attribution model rewards, where each one breaks, and a practical default for stores under $5M.
Sooner or later two of your partners will touch the same customer: a review blog introduces the product in March, a coupon site catches the buyer at checkout in April. One sale, two claims, one commission. Your attribution model is the rule that settles it — and because it decides who gets paid, it quietly decides what kind of partners your program attracts.
The three models that matter
Last click pays the partner whose link the customer used most recently before buying. It's the industry default and the easiest to reason about: the newest cookie simply overwrites the old one. It rewards partners who are close to the purchase decision — comparison pages, deal newsletters, coupon sites.
First click pays the partner who introduced the customer, no matter what happens afterward. The first cookie wins and later clicks don't replace it. This rewards discovery: the in-depth review, the tutorial, the newsletter that put your product on someone's radar weeks before they were ready to buy.
Split or multi-touch divides the commission across several touches. It sounds fairest and is genuinely useful at enterprise scale, but for a store with dozens of partners it multiplies disputes instead of resolving them — now two people argue about percentages instead of one person winning. Most WordPress-scale programs should skip it.
What each model does to your partner mix
Attribution is an incentive, and partners respond to it faster than you'd expect. Run last click and coupon sites flourish, because intercepting an already-decided buyer is exactly what they do well — see the coupon-site trade-offs before deciding whether that's a feature or a bug. Run first click and content creators flourish, because their early-funnel work can no longer be overwritten at the last second by a discount popup.
That's the real question to answer: which behavior do you want more of? If your product needs explanation — courses, memberships, anything with a considered purchase — first click protects the partners who do the explaining. If you sell an impulse-friendly product where the last nudge genuinely closes the sale, last click matches reality well enough.
The overwrite question, precisely
The mechanic underneath all of this is small: when a visitor who already has a referral cookie clicks a second partner's link, do you overwrite the cookie or keep the original? "First wins" (keep) and "last wins" (overwrite) are the two honest answers, and either is defensible — what isn't defensible is not knowing which one your software does. Affiliate Factory WP makes it an explicit tracking setting, and the referral record shows which visit produced the sale, so when a partner asks "why wasn't that mine?" you can answer with data instead of a shrug. You can watch how a referral ties back to its originating visit in the live demo.
Whatever you choose, write it into your program terms in one plain sentence: "If several affiliates refer the same customer, the commission goes to the first/most recent referring link within the tracking window." Most attribution disputes are really documentation disputes.
A default that works
For most stores under a few million in revenue: last click with a first-wins exception you can live without, or plainly, pick last click unless content partners are the program's backbone — then pick first wins and say so loudly in recruiting, because it's a genuine selling point to creators tired of being overwritten. Pair either with a sensible cookie window, keep self-referrals excluded, and revisit the choice once a year with your program numbers open — not more often. Attribution changes retroactively confuse everyone; make the rule once, publish it, and let partners build on stable ground.