In affiliate marketing, numbers tell the real story behind every partnership, click, and sale. The right combination of key performance indicators (KPIs) can help you create an affiliate marketing strategy that brings real value to your business.
From affiliate marketing conversion rates to the return on investment of your marketing materials, understanding key metrics is the difference between guesswork and a data-driven approach to reach new customers. Keep reading to learn more about what affiliate marketing entails and discover 20 of the most important affiliate marketing KPIs.
What is affiliate marketing?
Affiliate marketing is a strategy where brands partner with promoters, called affiliates or affiliate marketers, to share content and drive traffic, leads, or sales through unique referral links. When someone clicks on an affiliate link and completes a purchase, the affiliate earns a commission on the conversion.
There are several types of affiliate marketing programs, including pay-per-click, pay-per-lead, and pay-per-sale models, each offering different ways for affiliate marketers to earn a commission based on the desired customer action.
For brands, affiliate marketing strategies are cost-effective, scalable, and low-risk since payments are tied directly to performance. By leveraging the credibility and audiences of trusted affiliates, companies can expand their reach, increase conversions, and build brand awareness without significant upfront advertising costs.
How affiliate marketing works
Affiliate marketers may promote a company’s products or services using their own content, such as blog posts, social media, email campaigns, or videos, to their established audience. Alternatively, they might utilize brand-furnished marketing materials—for example, infographics or professional product images.
Similar to any internal ad campaign, a strong affiliate program closely tracks KPIs to measure how well the active affiliates are performing. By monitoring relevant metrics, a business can work toward attracting high-value customers with strong lifetime value, plus keep its affiliate partners aligned on shared growth goals and strategies.
20 key affiliate marketing metrics
- Affiliate average order value (AOV)
- Affiliate click-through rate (CTR)
- Affiliate content and link placement performance
- Affiliate conversion rate
- Affiliate cost per acquisition (CPA)
- Affiliate customer lifetime value
- Affiliate earnings per click (EPC)
- Affiliate engagement rate
- Affiliate fraud rate
- Affiliate link click-to-sale time
- Affiliate program activation rate
- Affiliate program growth
- Affiliate return on ad spend (ROAS)
- Affiliate return on investment (ROI)
- Affiliate retention rate
- Affiliate revenue per visitor (RPV)
- Average affiliate commission rate
- Mobile vs. desktop performance
- New vs. returning visitor conversion rate
- Traffic source distribution
The primary function of digital marketing is to attract organic traffic through search engines, social media platforms, and other digital channels, with the goal of converting these impressions into loyal customers. Affiliate marketing plays a vital role in this strategy by extending a brand’s reach through trusted partners and targeted promotions.
To evaluate if these efforts are paying off, you need to measure the performance effectively. The following affiliate marketing metrics can provide clarity, revealing which affiliates, campaigns, and marketing materials are driving real results—and where there are opportunities to improve. Use the following KPIs when making data-driven decisions about where to focus your affiliate marketing efforts.
1. Affiliate average order value (AOV)
Average order value for affiliate-driven orders measures the average revenue earned per transaction driven by affiliate marketing. You can find the revenue and order data in your ecommerce dashboard or affiliate tracking software.
Typically, AOV varies broadly by industry, but a higher AOV indicates more revenue per customer or per affiliate (which can directly improve return on investment (ROI) without increasing traffic). You can increase your AOV for affiliates through tactics like product bundling, volume discounts, or free shipping minimums that encourage customers to spend more per order.
The formula for finding AOV for affiliate-driven orders is:
Average order value for affiliates = Total revenue / Number of orders driven by affiliates
2. Affiliate click-through rate (CTR)
Click-through rate for affiliates is one of the essential metrics for measuring the flow of affiliate traffic, because it tracks how many people click on an affiliate link after viewing it. Essentially, it measures how successful affiliate content is at driving traffic. You can access clicks and impressions data through your affiliate platform or analytics tool. Strive for meeting the baseline CTR for affiliate links of 0.5%, while any CTR higher than 1% is exceptional.
The formula to find CTR is:
Affiliate click-through rate = (Number of clicks / Number of impressions) x 100
3. Affiliate content and link placement performance
This metric evaluates the effectiveness of affiliate link positioning by analyzing click-through rates, heat map data, and conversion tracking to determine how well marketing content and links are positioned on an affiliate’s website or social media post. Placement may not seem like an essential key performance indicator for affiliate marketing campaigns, but if you’ve ever found yourself confused on a disorganized landing page littered with banner ads, then you know the importance of effective user experience (UX) design—or rather, the impact when there’s a lack thereof.
Poor link placement can frustrate users and reduce conversions, while strategic link placement maximizes engagement. Aim for clean, uncluttered web pages where affiliate links are in the upper half or integrated naturally into content.
4. Affiliate conversion rate
Conversion rate is the percentage of visitors who complete a target action after clicking an affiliate link, such as making a purchase or signing up for a newsletter. You can find conversion and click data in your affiliate management dashboard or Google Analytics dashboard.
Conversion rate is king among affiliate marketing KPIs because it directly reflects how your marketing channels are performing. The average conversion rate range is between 1% and 3%, but top affiliates surpass 5%.
Use this formula to find conversion rate:
Conversion rate = (Number of conversions / Number of clicks) x 100
5. Affiliate cost per acquisition (CPA)
Cost per acquisition (not to be confused with cost per lead) compares how much money you’re paying your affiliate partners against the revenue they’re earning for your business. Find this cost and acquisition data in your CRM or affiliate program reports.
Affiliate program goals will vary between industries, but your cost per new customer acquired should always be lower than your affiliate revenue KPIs, like average order totals or lifetime values. Often, affiliates are only paid a commission per sale, in which case you needn’t worry about this metric. But it’s a useful number to know if you’re paying content creators, brand ambassadors, or other promoters to primarily post affiliate content.
To find your CPA, use this formula:
Affiliate cost per acquisition = Total affiliate marketing costs / Total number of customer acquisitions
6. Affiliate customer lifetime value
This metric quantifies the average revenue generated by a customer throughout their entire relationship with your brand as a result of affiliate marketing. Knowing customer lifetime value can help you assess the long-term value of customers you’ve acquired through affiliate marketing. You can find the sales and customer data needed to calculate affiliate customer lifetime value through your CRM, ecommerce platform, or analytics software.
Customer lifetime value ultimately reflects brand loyalty. The benchmark for customer lifetime value will be unique to your brand, as it varies widely between industries and business models. A high customer lifetime value can signal that your business is offering a consistent level of service—you’re keeping customers happy so that they come back to you, instead of going to a competitor.
The formula to find customer lifetime value is:
Affiliate customer lifetime value = Average purchase value x Average purchase frequency x Average customer lifespan
7. Affiliate earnings per click (EPC)
Find earnings and click data through your affiliate dashboard. Affiliate earnings per click (EPC) is a vital metric for any affiliate marketing strategy because it compares the revenue brought in by an affiliate link against the average cost per click (CPC). High-performing affiliates produce a favorable EPC-over-CPC, so review both metrics regularly to keep a pulse on the effectiveness of your affiliate program.
The formula for finding EPC is:
Affiliate earnings per click = Total earnings / Number of clicks
8. Affiliate engagement rate
Affiliate engagement rate demonstrates how actively affiliate marketers are promoting your products or services to their audiences. It also measures their interactions with your affiliate marketing platforms, like logging in to their affiliate dashboard or accessing your marketing materials. Of course, it’s up to each company to determine how it wants to define “engaged”—for example, maybe you focus on the number of affiliates who participated in a promotions campaign within the past 90 days.
Your affiliate platform will track engagement data, such as logins and promotional participation. A high affiliate engagement rate signals you’re working with partners who want to promote your brand—and the higher the rate, the higher the likelihood of conversions.
The formula for finding an affiliate engagement rate is:
Affiliate engagement rate = (Number of engaged affiliates / Total number of affiliates) x 100
9. Affiliate fraud rate
Tracking fraud helps you determine whether your affiliate partners are trustworthy, so you can safeguard your business’s reputation and financial health. Affiliate fraud (or affiliate abuse) occurs when an affiliate marketer employs deceptive or prohibited tactics to generate false leads or sales, thereby increasing their own commission. Unfortunately, every affiliate program is likely to experience some type of fraud, thanks to the prevalence of AI bots and other ill-intentioned actors. In fact, nearly 20% of all affiliate traffic is fraudulent.
Identifying affiliate abuse quickly will ensure your budget is going toward attracting genuine customers. Keep an eye out for illegal activities, scams, and other tactics that violate the terms of your affiliate agreement. Use Google Analytics (or your website analytics provider of choice) to help you identify purchase fraud, fake leads, and cookie stuffing. Periodically review referring URLs to identify prohibited sources or paid traffic, and investigate any unusual spikes in activity, especially if they’re from unfamiliar sources or regions where your products aren’t typically popular.
If you uncover fraud or abuse, take action right away to prevent additional losses and to signal to other affiliates that you’re committed to enforcing your agreement. You might ban the affiliate from your program or even report them to authorities—for example, if the fraud involves stolen credit card information.
The formula for finding affiliate fraud rate is:
Affiliate fraud rate = (Fraudulent sales / Total sales) x 100
10. Affiliate link click-to-sale time
This affiliate marketing metric reflects affiliate link efficiency. It tracks the time between the initial click and the final checkout. While sales are the end goal, a trend of hesitancy among customers can tell an enlightening story about the customer journey, alerting your team to potential roadblocks in the purchasing process. For example, if shoppers often stall on the payment page, it might indicate friction points, such as limited payment options or slow load times.
The formula for affiliate link click-to-sale time is:
Affiliate link click-to-sale time = Sum of all click-to-sale times / Number of conversions
To collect click-to-sale times, ensure your website and ad campaigns are set up to track clicks and conversions. Platforms like Google Ads have analytics dashboards that track the pixels and cookies in your ad campaigns to monitor user engagement. To calculate the click-to-sale time, subtract the ad click timestamp from the conversion timestamp to find the elapsed time.
11. Affiliate program activation rate
You can find activation data in your affiliate management platform or CRM. Affiliate program activation rate is the percentage of affiliates who are actively promoting your brand since joining your program. A good activation rate, typically 10% or higher, indicates your affiliates find your program appealing, easy to engage with, and financially beneficial. A low rate may suggest issues with recruiting, onboarding, communication, or the affiliate incentive structure.
The formula for affiliate program activation rate is:
Affiliate program activation rate = (Number of active affiliates / Total number of affiliates) x 100
12. Affiliate program growth
Affiliate program growth measures the number of affiliate marketers who have joined your network to promote your brand over a certain period of time. This metric can highlight program expansion or stagnation; the latter could signal the need to increase your affiliate recruitment efforts. Aim for steady month-over-month growth, though targets vary by industry and company size.
The formula for determining affiliate program growth is:
Affiliate program growth = (Number of total affiliates currently - Total number of affiliates in the last period) x 100
13. Affiliate return on ad spend (ROAS)
Recruiting affiliates who are likely to promote your brand can take effort and money. You may be spending money on advertising to find the right affiliates, which can be a significant cost for your affiliate program. It’s important to know whether, and how effectively, this cost is recouped.
Return on ad spend is one of the most essential affiliate marketing metrics and one of the easiest to calculate. It helps you evaluate the efficiency and profitability of an affiliate marketing campaign by showing how much revenue you’ve generated per dollar spent. A high ROAS indicates that your affiliate partners are driving strong, cost-effective conversions, while a lower ROAS may signal the need to optimize underperforming channels or adjust your commission structure.
The formula to find ROAS is:
Affiliate return on ad spend = Total revenue from affiliate marketing campaign / Total cost of affiliate marketing campaign
14. Affiliate return on investment (ROI)
Return on investment measures the profitability of your affiliate program. Even if affiliates only make a commission, you’ll likely still be spending money on recruitment ads, affiliate management software, marketing materials to share with them, and the labor cost of someone to manage the affiliate program.
The formula for ROI is:
Affiliate return on investment = [(Affiliate marketing revenue - Affiliate marketing costs) / Affiliate marketing costs] x 100
15. Affiliate retention rate
The affiliate retention rate tells you how many affiliates remained in your program in a given period. A low affiliate retention rate indicates a high number of affiliate partners are abandoning the program, indicating poor performance, poor fit, poor management, or a combination of these factors.
The formula for finding affiliate retention rate is:
Affiliate retention rate = (Number of affiliates at end of period - New affiliates) / Total affiliates at start of period
16. Affiliate revenue per visitor (RPV)
Similar to EPC and other affiliate marketing metrics concerned with program cost, affiliate RPV looks at the average revenue earned for each visitor who arrived from an affiliate link. You can find total revenue and visitor counts in your CRM analytics dashboard.
Knowing this metric helps you compare visitor quality across affiliates and campaigns.
The formula to find RPV is:
Affiliate revenue per visitor = Total Revenue / Number of visitors
17. Average affiliate commission rate
You can attract top-performing affiliate marketers with the right combination of incentives. The most common incentive is a commission of the affiliate revenue earned, with commission rates typically ranging from 5% to 30%. An affiliate program may also have tiered commission structures to encourage better performance. You can find commission payout data in your affiliate program reports.
The formula to find average affiliate commission rate is:
Average affiliate commission rate = (Total commission payouts / Total affiliate revenue) x 100
18. Mobile vs. desktop performance
Platform- or device-based key performance indicators highlight what consumers use to arrive at your product or service via an affiliate link. As of September 2025, data shows that nearly 58% of global online traffic comes from mobile devices, while 42% comes from desktops.
Tracking this data can reveal trends among an affiliate’s audience targeting and engagement. For example, perhaps 60% of an Instagram influencer’s audience clicked a specific affiliate link from a mobile device, while 40% did so from a desktop computer. Knowing this information could help you prioritize and optimize your marketing materials accordingly. Track device-based performance through your analytics platform, which segments traffic by device.
19. New vs. returning visitor conversion rate
Keeping an eye on your overall new vs. returning visitor conversion rate can help support budget-making decisions around your affiliate marketing efforts. If you have far more returning customers than new customers, this will positively impact their lifetime value, but it signals you need to put more resources into affiliate marketing to expand your customer base and attract new customers. You can access visitor segmentation in Google Analytics or your CRM.
The formula for finding new vs. returning visitor conversion rate is:
New vs. returning visitor conversion rate = (Conversions / Visitors) x 100, segmented by new or returning visitors
20. Traffic source distribution
Traffic source distribution reveals where your website visitors originate, whether that’s from an affiliate’s website, social media post, or email campaign. Tracking these sources helps you understand which affiliates or channels are driving the most valuable traffic. Pinpointing the source will allow you to shift your affiliate marketing strategy accordingly. For instance, you can either move more resources to top-tier marketing channels for better customer retention or reallocate some ad spend to other digital channels where you might find new customers. Aim for a healthy mix of sources, with no single channel driving more than about 50% of your total traffic.
Affiliate marketing metrics FAQ
What is a KPI in affiliate marketing?
A key performance indicator, or KPI, in affiliate marketing is a measurable metric a business uses to track progress toward specific affiliate marketing goals. Common affiliate KPIs include conversion rate, click-through rate, and average order value, among other metrics that help evaluate campaign performance. By monitoring these metrics, a business can gain deeper insights into what is working well and pinpoint necessary improvements for higher returns on its affiliate marketing investments.
How can you measure the success of affiliate marketing?
You can measure the success of affiliate marketing campaigns by tracking KPIs within your affiliate network. Focus on indicators such as conversion rate, click-through rate, and average order value to see how effectively your affiliates drive sales. These metrics will help you determine which partnerships and campaigns are delivering the strongest ROI for your business.
What is a good ROI for affiliate marketing?
While a “good” ROI varies significantly between industries and company sizes, the average amount to strive for is around 400%, or $5 earned for every $1 spent, though some well-established businesses might aim for as high as 1,400%. In general, a good ROI for affiliate marketing is one that indicates you’re earning more than you spend, or achieving a positive return on your investment. You can calculate ROI by using this formula: ROI = (Net profit / Investment) x 100.
