Affiliate 101: paying partners for the results they bring

Affiliate marketing pays partners for results. A brand (the advertiser, also called the merchant) gives independent publishers a tracked link or a personal code; when someone follows it and buys, signs up or applies, the publisher earns an affiliate commission. Partner marketing is the wider name for the same model when the partners also include other brands, apps and creators.

• What it is: distribution through other people's audiences, paid on performance.
• Who runs it: the brand, usually through an affiliate network or a partnership platform that tracks, validates and pays; the IAB UK and PwC study covers networks, software platforms and the large in-house programmes⁴.
• How it is priced: mostly a commission on each sale, sometimes a fee per lead or action, and sometimes a fixed placement fee on top.
• Best for: conversion, customer acquisition and advocacy and referral.
• Weak for: building a brand from nothing; most partners work at the very end of the purchase.
• As of: October 2026.

Every programme follows the same five steps, whether a network runs them or the brand does it in-house:

Three ideas decide who gets paid:

• The attribution window is how long after a click a sale still counts for the partner (attribution window). The brand sets it in the programme terms.
• Last click is the usual rule: when several partners touched the same purchase, the last one before the sale takes the whole commission. It is simple to pay, but it rewards position, not influence (attribution).
• The browser has its own say. Apple's WebKit, the engine behind Safari, deletes the script-written storage of a site after seven days without interaction when the visitor arrived from a known tracking domain with tracking details added to the link, and caps cookies set by scripts on such a landing page at 24 hours⁶. A 30-day window on paper can therefore be much shorter in practice. Ask your network exactly how it records a click, and how that record survives browser limits.

CDNow, an online music shop, launched its BuyWeb programme in November 1994, paying music sites for albums they sold; Amazon launched its Associates programme in July 1996 and made the model famous¹. Networks then grew up to run many programmes for many brands.

Fraud followed the money. In one widely reported case, eBay's top affiliate was sentenced to five months in prison for wire fraud after a cookie-stuffing scheme; court documents showed he had earned $28 million in commissions from eBay¹¹.

Regulators applied their advertising rules to the channel. The US Federal Trade Commission (FTC) revised its Endorsement Guides in 2009 and again in June 2023⁸. In the UK, the Committee of Advertising Practice (CAP) published affiliate guidance in March 2017 under the title "same rules, new guidance"⁹. Since 2025 the platforms and the courts have joined in: Google tightened the Chrome Web Store's affiliate rules in March 2025¹², after creators sued PayPal's Honey extension over commissions¹⁴.

Affiliate programmes run wherever people shop online, but few markets publish audited figures. The longest public series is the UK's. The IAB UK and PwC put advertiser spend on affiliate marketing at £554 million in 2017, up 15.1% from £482 million³, and estimated that it generated £8.9 billion in sales that year, up 9.2%, with retail the largest sector at 43%³⁴. In 2020 spend grew 10% to £627 million, and 41% of it was on smartphones⁵. The study was re-scoped in 2017 to the networks, platforms and in-house programmes it could see clearly, so years before and after are not directly comparable⁴.

• Americas: Amazon's Associates programme, born in the United States, still publishes its own commission table there², and US rules on endorsements are set by the FTC⁷.
• Europe: the UK has the most detailed spend data³⁵ and some of the most specific advertising guidance for affiliates⁹¹⁰.
• Middle East and Africa, Asia-Pacific: we found no comparable public, audited measurement of affiliate spend. Ask networks for figures for your market, and how they were counted.

• Conversion: the classic use, in retail and e-commerce, the largest UK sector⁴, and bookings in hospitality and travel.
• Customer acquisition and lead generation: comparison sites and lead partners for financial services, telecoms and B2B software, often paid per lead (CPL).
• Advocacy and referral: customer referral schemes and creator codes use the same tracking as affiliates.
• Market entry: local publishers bring an audience a new brand does not have yet.

In an integrated plan, affiliates usually sit at the end of the journey, collecting demand that advertising, influencers and search create.

There is no media cost: the brand pays commissions, network or platform fees and the people who manage partners. The commission model decides who carries the risk.

For a sense of public list rates, Amazon's US Associates table pays fixed rates by category: 10% for luxury beauty, 4.5% for physical books, kitchen and automotive, 3% for toys, furniture, home, sports and baby products, 4% for all other categories, and 0% for gift cards². Those are Amazon's own rates as of October 2026; other programmes set theirs freely, and networks and platforms charge their own fees, so ask for both in writing. Judge the total against cost per acquisition (CPA) and return on ad spend (ROAS) after returns.

Budget for the work as well as the commissions. Someone has to recruit and approve partners, write the terms, check creative and disclosures, review traffic sources, validate each period's sales and answer partners' questions. Set the validation period, the time before a sale is confirmed and paid, long enough to cover your returns policy, and say in the terms what happens to commission on a cancelled order.

This is a summary, not legal advice.

• United States. The FTC treats an affiliate link as a material connection that must be disclosed. Its guidance says "affiliate link" on its own, or a "buy now" button, is not an adequate disclosure, while "paid link" right next to the link should be; it suggests wording such as "I get commissions for purchases made through links in this post."⁷ The Guides are not regulations, but the FTC can act against practices that break them under the FTC Act⁷⁸.
• United Kingdom. The CAP Code applies to affiliate marketing, including on the affiliate's own site and social media. Banner ads, branded emails and cashback sites are usually obvious as ads; blogs, vlogs, social posts, news sites and voucher sites need a clear label such as "Ad"; only the content about affiliate-linked products counts as advertising⁹. Since 6 April 2025 the Digital Markets, Competition and Consumers (DMCC) Act sets the unfair-practice rules, including the ban on fake and concealed incentivised reviews¹⁰.
• Shared responsibility. The ASA published its guidance because brands and affiliates were blaming each other for breaches⁹; under both regimes the brand cannot hand compliance to the partner.
• Platforms. Chrome extensions may use affiliate links only when they give the user a direct benefit, must disclose the programme on the store listing, in the interface and before installation, and need a user action before a link, code or cookie is applied¹².
• Data. Tracking relies on identifiers in the browser or on servers; consent and data-protection rules apply to them in each country, as to any tracking.

• Paying for sales you already had. Cashback and coupon partners often meet shoppers who have already decided. Test with incrementality methods, such as a holdout test, before scaling them.
• Last click invites games. Creators sued PayPal's Honey extension in 2025, alleging it took credit for sales at checkout by replacing their affiliate tracking¹⁴. In November 2025 a federal judge dismissed the suit, finding the creators had not shown they were entitled to those commissions under their merchant contracts¹³. Whatever the courts decide, the lesson for brands is to define in the contract which touch earns the commission.
• Cookie stuffing. Planting tracking cookies on people who never clicked, so that the fraudster is credited for later purchases, has led to prison terms¹¹. Watch for clicks without visits and partners whose traffic sources you cannot see.
• Bidding on your own name. Partners who buy search ads on your brand name can collect commission on customers who were already looking for you; decide in the terms whether that is allowed.
• Browser limits. Tracking prevention can cut the real window to days or hours⁶; numbers can fall without any change in partner quality.
• Series that move. Even the best public data changes scope, as the IAB UK study did in 2017⁴; compare like with like.

• Platform rules in force. Google's Chrome Web Store policy on affiliate extensions has applied since March 2025¹².
• Litigation on credit. The Honey cases put last-click credit in front of the courts; the first ruling went against the creators¹³, and commentators expected them to face a hard road¹⁴.
• Stronger UK enforcement. The DMCC Act's consumer rules have applied since April 2025¹⁰.
• Less tracking in the browser. Safari's limits on tracking storage⁶ push programmes towards tracking they control.

Choose affiliate marketing when the objective is a measurable action and you can track, validate and police it. Pair it with disciplines that create demand, such as digital advertising and influencer marketing, and judge it with the methods in measuring effectiveness. See the affiliate discipline page, the hub for performance marketers and which mix for which objective.