Affiliate marketing is a performance-based advertising channel in which publishers earn commissions for driving consumer actions on behalf of advertisers. US affiliate spending is projected to reach $13.81 billion in 2026, according to a September 2025 EMARKETER forecast. The channel now sits at an inflection point: generative AI chatbots are reshaping how consumers discover and compare products, creators are claiming a growing share of affiliate budgets, and measurement frameworks still struggle to capture affiliate's full value. This FAQ covers affiliate market size, publisher types, AI disruption, and what marketers should prioritize in 2026.

What is affiliate marketing?

Affiliate marketing is a performance-based advertising model in which publishers (affiliates) promote an advertiser's products or services and earn a commission when consumers take a specified action, typically a purchase through a tracked link. Affiliates span a wide range of business types: editorial content sites like Wirecutter, loyalty and cash back platforms like Rakuten Rewards, social media creators, coupon and deal publishers, and technology partners such as card-linked offer providers.

The model operates through affiliate networks, including CJ, Awin, and Partnerize, which connect advertisers with publishers, manage tracking, and process payments. Advertisers pay only for measurable results, making affiliate one of the more cost-accountable channels in digital marketing.

How big is the US affiliate marketing industry?

US advertisers will spend $13.81 billion on affiliate marketing in 2026, up 11.3% from $12.42 billion in 2025, according to a September 2025 EMARKETER forecast. That growth rate is significantly higher than the growth rate of US retail ecommerce sales overall (6.7%) during that period, per a February 2026 EMARKETER forecast.

Affiliate also drives a large share of online purchasing. The channel will generate an estimated $241.03 billion in US ecommerce sales in 2026, according to the same EMARKETER forecast. This suggests the channel is no longer a niche tactic but a core component of ecommerce infrastructure.

What types of affiliate publishers work with brands?

The affiliate ecosystem includes several distinct publisher categories, each serving different roles in the consumer journey:

• Cash back, loyalty, and rewards publishers. Platforms like Rakuten Rewards claimed the largest share of affiliate ad spend in 2024 at 35%, per a June 2025 Performance Marketing Association (PMA) report cited by EMARKETER.
• Content publishers. Editorial review and recommendation sites like Wirecutter accounted for 16% of spend, per the same PMA data. Their role is expanding as large language models (LLMs) draw on this content.
• Creators and influencers. The fastest-growing category, with budgets shifting toward creators who combine awareness and conversion in a single integration.
• Discount and coupon publishers. These captured 42.4% of US affiliate revenues in H1 2025, according to Awin data cited in an October 2025 EMARKETER report.
• Technology partners. Cart-abandonment tools, card-linked offers, and BNPL providers now claim about 7% of budgets, up from 5% in 2021, per PMA data cited by EMARKETER.

Why are creators and influencers gaining share in affiliate marketing?

Content creators represent the fastest-growing publisher type in affiliate marketing. On Awin's network, their share of revenue rose from 15.9% to 19.5% year-over-year, according to an October 2025 EMARKETER report.

Three factors are driving that growth:

• Full-funnel value. Creators address awareness, consideration, and conversion in a single integration. Newer advertisers entering affiliate are prioritizing content and influencers over traditional tactics, the report noted.
• Compounding returns. By the eighth integration with the same YouTube creator, affiliate link clickthrough rates reach 1.8x the rate of the first integration, according to Agentio data cited by EMARKETER. Buyers typically need three to four creator exposures before purchasing, per an EMARKETER and impact.com survey cited in the same article.
• AI-powered partner matching. Affiliate networks now use AI to recommend creators of any size, reducing the friction of partner discovery.

How is generative AI disrupting affiliate marketing?

Generative AI chatbots are reshaping the shopping journey that affiliate marketing depends on. Shopping-related queries on ChatGPT grew faster than any other query type between December 2024 and June 2025, according to Sensor Tower data cited in an October 2025 EMARKETER report. Consumers who use genAI have adopted it for price comparison (54%), deal finding (41%), and review checking (41%), per a July 2025 Wildfire Systems survey cited by EMARKETER.

This creates a core tension for the channel. AI chatbots perform the same tasks that affiliate publishers built businesses around: product comparison, deal hunting, and recommendation. When a consumer gets those answers inside a chatbot rather than clicking through a publisher's link, the channel's attribution mechanism breaks and the tracked link that triggers an affiliate commission never occurs.

What role does affiliate content play in generative engine optimization (GEO)?

Affiliate content has become a critical input for the large language models (LLMs) powering AI chatbots. Almost 70% of the sites cited in ChatGPT's mentions of eyewear brand Zenni came from affiliate marketing content, according to an October 2025 EMARKETER report. More than one-quarter of OpenAI's content partnerships since 2021 have been with publishers that operate scaled affiliate commerce content, per OriginalityAI data cited in the same report.

This indicates that affiliate publishers' product reviews, shopping guides, and recommendation content serve as trusted sources that LLMs draw on when answering consumer queries. For brands, affiliate content is now a key component of generative engine optimization (GEO), ensuring a brand appears favorably in AI-generated responses.

What are the measurement challenges in affiliate marketing?

Affiliate marketing remains difficult to measure accurately within marketing mix modeling (MMM) frameworks. Among marketers using MMM, 27.3% fold affiliate into a general performance bucket and 14.8% do not represent it at all, according to an EMARKETER and Rakuten Rewards survey.

The problem extends beyond categorization:

• Planning gaps. 43.2% of marketers either do not incorporate affiliate data into campaign planning or only do so after budgets are set, per the same report.
• Slow optimization cycles. Only 14.8% feed MMM insights into live optimization weekly. Most do it quarterly (34.1%) or ad hoc (25%).
• Limited testing. 70.6% of marketers who do not see a path to their desired granularity have not run geo-split tests or incrementality lift studies.

These gaps mean affiliate's actual revenue contribution is often undercounted, making it harder for the channel to secure budget increases.

What challenges do affiliate publishers face from Google and AI?

Affiliate publishers confront two converging distribution threats. Google continues to adjust search rankings and expand AI Overviews, both of which reduce publishers' organic traffic. Between May and August 2025, Wirecutter's visibility in Google search results dropped by over 60%, according to GSQi analysis cited in an October 2025 EMARKETER report. Close to 7 in 10 publishers report being concerned or very concerned that Google's changes will hurt their affiliate businesses, per Performance Marketing Association data cited in the same report.

Publishers are working to diversify traffic sources by turning to channels like Reddit, Discord, and email newsletters to offset losses.

How are value-seeking consumers reshaping affiliate marketing?

Affiliate marketing has historically performed well during periods of economic uncertainty, and 2025 continued that pattern. Discount and promotions publishers claimed 42.4% of US affiliate marketing revenues in H1 2025, up from 39.7% a year earlier, according to Awin data cited in an October 2025 EMARKETER report.

Coupon reliance is growing across publisher types. Seven of the 10 largest affiliate publisher types increased coupon use in H1 2025. Among email publishers, 50.1% of sales included a coupon, according to Awin data cited by EMARKETER.

How should marketers optimize their affiliate programs in 2026?

Marketers should focus on four areas to maximize affiliate's value in 2026:

1. Move beyond last-click attribution. Rising AI chatbot use will deprive publishers of the click-based credit they need to sustain content production. Test multi-touch or data-driven attribution models.
2. Build GEO expertise. LLMs draw heavily on affiliate content when answering shopping queries. Understand which publishers' content appears in AI-generated responses and invest accordingly.
3. Invest in long-term creator partnerships. Sustained collaborations with the same creator generate higher clickthrough rates and consumer trust.
4. Integrate affiliate into MMM. Ensure your modeling framework captures affiliate as a distinct channel rather than folding it into a generic performance bucket.

We prepared this article with the assistance of generative AI tools and stand behind its accuracy, quality, and originality.

EMARKETER forecast data was current at publication and may have changed. EMARKETER clients have access to up-to-date forecast data. To explore EMARKETER solutions, click here.