Influencer Attribution Explained: Discount Codes, UTM Links, Affiliate Links and Lift Studies

An influencer marketing campaign may generate thousands of views and hundreds of clicks, but the most important question for a brand is whether the campaign actually contributed to sales, leads, or other business outcomes.

That is where influencer attribution comes in. It helps brands connect measurable outcomes with interactions involving influencer content through methods such as discount codes, UTM links, affiliate links, and lift studies.

However, each method has limitations. A customer may use a discount code after watching a video, click an influencer’s link and complete the purchase on another device, or watch content without clicking and return to the store later through search or a paid advertisement.

Therefore, a sale recorded against a campaign does not necessarily mean the influencer was its sole cause. Equally, a lack of recorded sales does not automatically mean the content had no influence on the customer’s decision.

This guide explains how each attribution method works, what it can and cannot establish, and how brands can choose a measurement approach that fits their campaign objectives. 

What Is Influencer Attribution

1. Discount Codes: A Direct Way to Track Code-Associated Sales

2. UTM Links: Tracking Traffic Sources and Campaigns

3. Affiliate Links: Connecting Conversions to Partners

4. Lift Studies: Did the Campaign Actually Generate Additional Results

5. Comparing Influencer Attribution Methods: Which One Should You Choose

6. How Should Brands Handle Cross-Device Purchases

7. What About Views That Do Not Lead to Clicks

8. How to Choose the Right Measurement Approach

9. Measuring TikTok Shop and Affiliate Campaigns

Contact Gravity Marketing to Improve Influencer Campaign Measurement

What Is Influencer Attribution

Influencer attribution is the process of connecting marketing interactions with specific actions, such as purchases, registrations, lead submissions, or app installs.

In influencer marketing, brands may want to understand how many orders were associated with a particular creator, how much revenue was recorded through a dedicated link, or whether a campaign generated additional sales compared with what might have happened without it.

Three concepts are particularly important:

• Tracking: Recording observable events, such as clicks, visits, orders, and conversions.

• Attribution: Applying defined rules to connect conversions with a marketing interaction, channel, or influencer.

• Incrementality: Estimating the additional outcomes that would not have occurred without the campaign, using an appropriate measurement design, such as an experiment or comparison group.

For example, if an ecommerce store records 100 orders using an influencer’s discount code, it can report 100 orders associated with that code under its tracking rules. However, this does not prove that all 100 orders would have been lost if the influencer had never published the content.

Similarly, if an analytics platform reports 500 purchases attributed to a particular traffic source, it shows what the platform assigned to that source under its attribution settings—not necessarily the campaign’s true incremental impact.

To establish a more complete measurement framework, start by selecting relevant metrics from Gravity Marketing’s Influencer Marketing KPIs guide, then choose tracking and attribution methods that help measure those metrics.

1. Discount Codes: A Direct Way to Track Code-Associated Sales

Discount codes allow brands to assign a unique promotional code to each influencer, such as SARA10 or CREATOR15. When a customer uses the code at checkout, the store can record the order as associated with that code.

This method is common in ecommerce campaigns, especially when influencer content encourages audiences to try a product or redeem a specific offer.

How Do Influencer Discount Codes Work

1. Assign a unique code to each influencer or campaign.

2. Communicate the code through videos, posts, Stories, or livestreams.

3. Record code usage when customers complete their purchases.

4. Review orders, revenue, discounts, cancellations, and returns.

5. Compare results across influencers using consistent reporting rules and measurement periods.

If customers use a particular code for 80 orders, the brand can identify those orders and calculate their associated revenue using its store data.

What Can Discount Codes Prove

Discount codes can help brands measure:

• The number of orders that used a specific code.

• The sales value recorded against those orders.

• The number of first-time customers, when reliable customer-history data is available.

• Differences in code usage, revenue, and average order value.

• Audience response to an influencer-associated promotional offer.

What Are the Limitations of Discount Codes

Customers may purchase without using the code. Someone might watch the influencer’s content, remember the product, and later buy it at full price. That purchase would not appear in the code’s recorded sales.

Code usage does not prove the content caused the purchase. A customer may discover the code on a coupon website, receive it from a friend, or have already decided to buy the product.

Code sharing can weaken attribution accuracy. Once a code spreads beyond the influencer’s original audience, purchases may be associated with the code even when another source influenced the customer.

Discount codes do not establish incrementality. They record code usage but cannot independently determine whether the customer would have purchased without the campaign.

Discount levels can affect performance. A code offering a larger discount may generate more redemptions, but this does not necessarily mean the influencer is more persuasive or better at generating demand.

When Should Brands Use Discount Codes

Discount codes are useful when the objective is to encourage purchases, compare promotional offers, or track sales associated with specific campaigns.

For a more complete view, combine them with dedicated tracking links rather than relying on codes alone.

2. UTM Links: Tracking Traffic Sources and Campaigns

UTM parameters are tags added to a website URL that help analytics tools identify the traffic source and campaign associated with a visit, provided the analytics setup is configured correctly.

A product link might include parameters such as:

• utm_source: The traffic source, such as an influencer or platform.

• utm_medium: The marketing channel, such as influencer or creator.

• utm_campaign: The campaign name.

• utm_content: The specific content, creative version, or influencer identifier.

Here is an illustrative example:

This is a demonstration URL using a non-production example domain, not a live campaign link.

How Should Brands Use UTM Links

1. Create a dedicated URL for each influencer, post, or platform, depending on the required level of detail.

2. Add consistent UTM parameters.

3. Direct audiences to the appropriate product page or landing page.

4. Verify that the analytics platform and ecommerce store record visits and conversions correctly.

5. Analyze sessions, conversions, and recorded revenue by source, campaign, and content.

Consistent naming is essential. If the same source is recorded as Influencer, influencer, and creator, reporting may split the data into separate categories.

What Can UTM Links Prove

When tracking is configured correctly, UTM links can help identify:

• Visits recorded from tagged URLs.

• The campaign and content associated with those visits.

• Conversions attributed to those visits under the analytics platform’s settings.

• Revenue recorded from campaign-associated visits, when ecommerce tracking is enabled.

• Performance differences across influencers, platforms, and creative assets.

What Are the Limitations of UTM Links

A click is not a conversion. A link may generate substantial traffic without producing the expected number of purchases or qualified leads.

A tracked visit does not prove purchase causation. If someone clicks an influencer’s link and later buys, the analytics platform may attribute the conversion to that link under its model. This does not establish that the influencer was the sole reason for the purchase.

Traffic-source information can be lost. Redirects, sharing links, transitions between apps and browsers, and analytics configuration issues can interfere with source tracking.

Cross-device journeys may be fragmented. If a customer clicks a link on a phone and completes the purchase on a laptop, the visit and purchase may be recorded as separate users or sessions unless a reliable method connects them.

UTM parameters do not track view-through influence. If someone watches influencer content and later searches for the brand independently, the UTM link alone cannot establish that the earlier content contributed to the later visit.

When Should Brands Use UTM Links

UTM links are especially useful for campaigns designed to drive traffic, generate leads, or direct audiences to product pages.

They become more valuable when combined with ecommerce data, discount codes, and properly configured conversion tracking.

3. Affiliate Links: Connecting Conversions to Partners

Affiliate links associate clicks and conversions with an influencer or partner identifier. Depending on the system, tracking may rely on cookies, other identifiers, or platform- and store-based tracking mechanisms to record eligible orders and calculate commissions.

Unlike a UTM link, which primarily labels traffic for analytics, an affiliate link usually operates within a referral-management system that determines which sales qualify for commission. Some systems use both methods together.

How Do Affiliate Links Work

1. Each influencer receives a unique referral link or identifier.

2. The influencer shares the link through their content or other channels.

3. The affiliate system records clicks and conversions under its tracking rules.

4. Eligible orders, cancellations, and returns are reviewed.

5. Commissions are calculated according to the affiliate program’s terms.

Commission rules vary by program. Brands should therefore define the attribution window, the treatment of canceled or returned orders, and which interaction receives credit when multiple sources are involved.

What Can Affiliate Links Prove

Affiliate links can help brands measure:

• Recorded clicks for each partner.

• Eligible orders associated with a referral identifier.

• Recorded sales value and commissions due under the program’s rules.

• Differences in partner performance when measurement conditions are consistent.

• Each partner’s contribution to sales recorded by the referral system.

What Are the Limitations of Affiliate Links

Tracking windows affect results. If a customer returns to purchase after the attribution window expires, the order may not be credited to the original referral.

Multiple partners may compete for attribution. A customer may click several affiliate links. The system might credit only one partner according to its rules, even if several sources contributed to the customer journey.

Privacy restrictions can affect tracking. Browser settings, cookie consent, and platform policies may limit the ability to connect clicks with subsequent conversions.

Links can be shared beyond the original audience. A referral link may be reposted or used on other websites, making it harder to identify the original influence on a purchase.

Recorded affiliate sales do not establish incremental impact. A customer might already intend to buy or have been influenced by another campaign before completing the purchase through an affiliate link.

When Should Brands Use Affiliate Links

Affiliate links are useful for commission-based partnerships and programs where brands need to compare partners, verify eligible sales, and calculate payouts.

Gravity Marketing’s guide to TikTok Shop Affiliate Marketing explains how affiliate tracking connects product promotion with eligible sales, commissions, and performance metrics.

4. Lift Studies: Did the Campaign Actually Generate Additional Results

Lift studies differ from discount codes and tracking links because they do not simply identify conversions associated with a campaign. They aim to answer a more important question:

How many additional results did the campaign generate compared with what would have happened without it

Lift studies estimate incremental impact by comparing outcomes for an audience exposed to a campaign with those of an appropriate comparison group, or by using a suitable experimental or quasi-experimental design.

How Does a Lift Study Work

In a simplified experimental design:

1. Define the eligible audience for the study.

2. Randomly assign people to an exposed group and a comparison group, when feasible.

3. Measure conversions in both groups over a defined period.

4. Compare conversion rates while accounting for differences in group sizes.

5. Estimate the increase associated with the campaign, within the limits of the study design and data.

For example, suppose the exposed group has a conversion rate of 6%, while the comparison group has a conversion rate of 4%. The difference is two percentage points.

Relative lift is calculated as follows:

In this example, the exposed group’s conversion rate was 50% higher than the comparison group’s rate.

However, this does not automatically mean the campaign increased total sales by 50%. That conclusion depends on group selection, sample size, measurement quality, the study period, and whether the results can be generalized to the intended audience.

What Can Lift Studies Prove?

When appropriately designed and implemented, lift studies can provide stronger evidence about:

• Whether a campaign contributed to higher conversion rates than a comparison group.

• The difference in conversion rates between the exposed and comparison groups.

• The potential incremental effect on sales, registrations, or other defined outcomes.

• The financial value of incremental results, when reliable cost and revenue data are available.

• Differences in impact across audience segments, when the study design and sample size support that analysis.

What Are the Limitations of Lift Studies

They require an appropriate design and sufficient data. Small samples, imbalanced groups, or unreliable measurement can produce inconclusive or inaccurate results.

Isolating an individual influencer’s effect can be difficult. If audiences encounter several influencers and paid advertisements during the same period, identifying each influencer’s independent contribution may require a carefully designed study.

Exposure may not be completely isolated. People in the comparison group may encounter campaign content indirectly, such as when someone shares it with them. This can affect the comparison.

Not every lift study is a randomized experiment. Before-and-after comparisons or non-randomized groups may be affected by seasonality, promotions, or changes in demand.

Results are specific to the study context. The same level of lift should not automatically be expected across different markets, periods, or campaigns.

When Should Brands Use Lift Studies

Lift studies are useful when a brand needs to understand whether a campaign generated additional outcomes beyond sales directly associated with links or codes.

They may require more time, data, and coordination than standard tracking. Brands should therefore consider them when the business decision is important enough to justify a suitable measurement design.

5. Comparing Influencer Attribution Methods: Which One Should You Choose

No single method answers every measurement question. The right choice depends on the campaign objective, the conversion being measured, the available tracking infrastructure, and whether the brand needs to estimate incremental impact.

Can Brands Combine Multiple Methods

Yes. Combining methods often provides a more complete picture than relying on one tracking mechanism.

For example, a brand can use:

• UTM links to identify traffic associated with each influencer.

• Discount codes to record purchases using specific offers.

• Affiliate links to calculate eligible partner commissions.

• Lift studies to estimate incremental campaign impact when appropriate.

However, brands should not simply add all reported results together. The same order may appear in multiple systems. Combining code-based sales and link-attributed sales without deduplication can inflate the reported total.

The better approach is to establish a primary source of truth for orders and revenue, then use the other methods to validate results and answer additional questions.

6. How Should Brands Handle Cross-Device Purchases

Cross-device purchases occur when someone views influencer content or clicks a link on one device and completes the purchase on another.

This creates a measurement challenge because analytics tools may rely on cookies, browser identifiers, or session identifiers that cannot reliably recognize the same person across devices.

Imagine a customer watches a video on their phone, clicks the product link, and returns to the website the next day on a laptop to complete the purchase. If the two visits cannot be reliably connected, the purchase might be recorded as direct traffic or attributed to another source.

To improve measurement accuracy:

1. Use dedicated influencer links and maintain consistent tracking parameters.

2. Configure conversion tracking in the ecommerce store and analytics platform, and test how data passes between them.

3. Use authenticated identifiers or order-level identifiers where available and appropriate under applicable privacy requirements.

4. Compare platform, store, and analytics reports while recognizing that they may use different definitions.

5. Document journeys that cannot be reliably connected rather than assuming every conversion can be tracked.

Even with strong tracking infrastructure, some customer journeys will remain unobservable or unconnected. Attribution data should therefore be treated as a record of what the system could measure, not a complete record of every marketing influence.

7. What About Views That Do Not Lead to Clicks

Influencer content may affect purchasing decisions even when viewers never click a link.

Someone might see a product in a video, search for the brand later, visit the store independently, or make a purchase after encountering another advertisement.

This creates a challenge for click-based attribution because a tracking link records interactions that pass through it. It cannot independently establish whether earlier content contributed to a later conversion.

Two concepts are particularly important:

• View-through attribution: A conversion is credited to a content or advertising exposure under defined rules and a specified attribution window, even when the user did not click.

• Incrementality: An estimate of whether the campaign generated additional outcomes compared with what would have happened without the exposure.

View-through attribution is not definitive evidence of causation. A person may see an advertisement because they are already interested in a product and then purchase for other reasons.

View-through reporting also varies between platforms, including the attribution window, eligibility requirements, and how a qualifying view is defined.

To avoid misleading comparisons, document the attribution window and view-through rules. Do not treat figures from two platforms as directly comparable unless their definitions and measurement methods are sufficiently aligned.

When the key question is whether the campaign actually made a difference, a suitable lift study may provide stronger evidence than attribution reports alone.

8. How to Choose the Right Measurement Approach

Start with the business question you want to answer, then select the method that best addresses it.

If the goal is to increase sales

Use discount codes, tracking links, or affiliate links. Review canceled orders, returns, and net revenue.

If the goal is to generate traffic or leads

Use UTM links and dedicated landing pages. Track completed actions rather than relying on click counts alone.

If the goal is to manage an affiliate program

Use clear referral identifiers and define commission eligibility before the campaign begins.

If the goal is to demonstrate incremental impact

Consider an appropriate experiment or lift study with a comparison group and a reliable measurement design.

Pre-Campaign Measurement Checklist

• Define the campaign objective and the conversion that represents success.
• Agree on definitions for orders, revenue, and eligible conversions.
• Assign dedicated links and codes to influencers where appropriate.
• Standardize UTM naming conventions.
• Test tracking before the content goes live.
• Define the attribution window and rules for multiple interactions.
• Document cross-device and view-through measurement limitations.
• Deduplicate orders and review cancellations and returns.
• Compare results with campaign costs using a consistent methodology.
• Distinguish attributed sales from estimated incremental sales.

Once the data has been collected, brands can compare results with costs to evaluate return on investment (ROI). However, ROI calculations are only as reliable as the underlying revenue and cost data and the method used to attribute outcomes to the campaign.

For more guidance, explore Gravity Marketing’s Influencer Marketing KPIs guide and its Performance Marketing guide to understand how tracking and conversions support performance-based campaigns.

9. Measuring TikTok Shop and Affiliate Campaigns

In social commerce campaigns, some purchases may be recorded directly within the platform, while others take place on the brand’s external website. The appropriate measurement method therefore depends on where the conversion occurs and which tracking tools are available.

For TikTok Shop campaigns, order data, referral information, and eligible affiliate sales can help brands evaluate the performance of creator content linked to the store. When creators direct audiences to an external website, brands may need dedicated tracking links and appropriate analytics configuration.

When comparing results, consider the following:

• Eligible sales: These are not necessarily the same as total orders. Canceled, returned, or otherwise ineligible orders may be excluded.

• Revenue: Clarify whether the reported figure represents gross order value or revenue after discounts and returns.

• Commissions: These represent affiliate-related costs or payouts, not independent evidence of profitability.

• ROAS and ROI: Define which costs are included. ROAS generally compares revenue with advertising spend, while ROI can account for a broader range of costs and returns, depending on the calculation used.

For more detail, read Gravity Marketing’s guide to TikTok Shop Affiliate Marketing.

Contact Gravity Marketing to Improve Influencer Campaign Measurement

A clear measurement framework helps brands understand campaign results, compare influencer performance, and make better-informed decisions about marketing budgets and channels.

Contact Gravity Marketing to discuss your campaign objectives and performance measurement requirements.

• Contact Gravity Marketing
• Email: info@gravity-media.net
• Phone: +20 101 492 2711
• Phone: +20 155 512 3155