The commerce pie is growing while the traffic pie shrinks

A caution before the numbers: affiliate market sizing is genuinely messy. Some trackers measure channel spend, others measure the software and platform layer that administers partner programs, and the two get quoted interchangeably. One widely cited platform-market figure puts 2025 at $22.6bn, larger than the channel-spend figure for the same year, because it is counting something else entirely.

So read the chart as a growth rate, not a bank balance. On that basis the direction is consistent across sources: just over $20bn in 2026, about $27.8bn by 2027, and roughly $38.4bn by 2030 at a 15.4% compound rate.

Creator-driven revenue is the fastest-moving slice

Creator affiliate revenue roughly doubled from $570m in 2021 to $1.1bn in 2024. That is a small share of the total and the steepest curve in it, which is why retailer program terms have been getting more competitive rather than less.

On the publisher side, around 86% of publishers expect their affiliate revenue to hold or rise. Set that against a search channel down a third and the strategic read is straightforward: the money is available, the free traffic that used to reach it is not.

What actually determines your share

Program terms are not uniform, and the difference between the best and worst available route for the same product is routinely larger than the difference between a good and a bad headline. Most publishers link to whichever program they happened to sign up for years ago, which means their realised rate is an accident of history.

Growth in the category is not the same as growth in your account. The pie expanding only helps if you are routing each product to the best-paying destination available for it.