UTM Tracking for Webgains: How to Build and Validate Affiliate Campaign Links

How Webgains’s tracking architecture interacts with UTM parameters

Webgains is one of Europe’s oldest and largest performance marketing networks, founded in 2000 and headquartered in the UK. It connects advertisers (merchants) and publishers (cashback sites, voucher and coupon aggregators, price comparison sites, content publishers, and CSS affiliates) across retail, fashion, financial services, technology, and subscription products. Webgains operates across the UK and major European markets.

When a publisher promotes an advertiser’s Webgains programme via an affiliate link, the click routes through Webgains’s clicks.webgains.com tracking infrastructure. Webgains records the click event for commission attribution using its own tracking system, then redirects the browser to the advertiser’s configured destination URL. Webgains’s tracking system — which handles click recording and commission payouts — operates entirely separately from GA4 UTM tracking and does not depend on or interfere with UTM parameters.

The consequence for UTM tracking: UTM parameters belong on the destination URL you configure in the Webgains Advertiser Hub for your programme, not on the publisher-facing tracking link. The Webgains publisher link is formatted and controlled by the platform; the destination URL is the configuration point you control as an advertiser. Paste the UTM-tagged destination URL generated by mlz build into your Webgains programme settings.

Webgains supports deep links — publishers can generate links that point directly to specific product pages or category pages on the advertiser’s site rather than the default programme landing page. Deep links introduce additional redirect complexity because product pages often have different URL handling than the main landing page. E-commerce platforms commonly enforce canonical URLs or perform trailing-slash normalization redirects on product paths, and these redirects do not always preserve query strings. For the full context of UTM parameter redirect chain validation, see the UTM tracking for developers guide.

Building Webgains destination URLs with mlz build

The most common UTM data quality problem in Webgains programmes is casing inconsistency: one campaign uses utm_source=Webgains (capitalized), another uses utm_source=webgains, and a third uses utm_source=web-gains. GA4 is case-sensitive and records these as separate traffic sources, making it impossible to report total Webgains affiliate performance accurately. mlz build eliminates this by enforcing lowercase-hyphenated values from structured input regardless of what the operator types.

The standard naming convention for Webgains programmes is utm_source=webgains, utm_medium=affiliate, and utm_campaign=[program-name-or-season]. Use utm_content to differentiate between creatives, promotional types, or publisher categories within the same programme configuration.

$ mlz build \
  --url "https://shop.example.com/landing" \
  --source "webgains" \
  --medium "affiliate" \
  --campaign "summer-sale-2026" \
  --content "cashback-publishers" \
  --validate

{
  "tracked_url": "https://shop.example.com/landing?utm_source=webgains&utm_medium=affiliate&utm_campaign=summer-sale-2026&utm_content=cashback-publishers",
  "params": {
    "utm_source": "webgains",
    "utm_medium": "affiliate",
    "utm_campaign": "summer-sale-2026",
    "utm_content": "cashback-publishers"
  },
  "destination_url": "https://shop.example.com/landing",
  "link_id": "lnk_wg_ss26_cb",
  "campaign_id": "cmp_summer-sale-2026",
  "stored": true,
  "created_at": "2026-07-03T10:00:00.000Z"
}

The tracked_url value is what you paste into the Destination URL or Default Landing Page field in the Webgains Advertiser Hub when creating or editing your programme. For deep link configurations where publishers link directly to product pages, generate a distinct destination URL for each product category using a category-specific utm_content value:

For naming conventions and how consistent casing prevents GA4 data fragmentation across affiliate sources, see the UTM naming conventions guide. To generate destination URLs programmatically across a large Webgains product catalog via the REST API, see how to build UTM links programmatically.

Validating the Webgains redirect chain with mlz check

Once you have a UTM-tagged destination URL, validate it end-to-end with mlz check before entering it into the Webgains Advertiser Hub. mlz check follows the complete redirect chain from your destination URL, confirms the server responds with a 200, and verifies query parameters are not stripped at any hop. Run this before your Webgains programme goes live and re-run it after any infrastructure change that touches URL handling — particularly important for deep-linked product pages where platform-level redirect rules may differ from the main landing page.

$ mlz check "https://shop.example.com/landing?utm_source=webgains&utm_medium=affiliate&utm_campaign=summer-sale-2026"

{
  "url": "https://shop.example.com/landing?utm_source=webgains&utm_medium=affiliate&utm_campaign=summer-sale-2026",
  "valid": true,
  "checks": [
    { "check": "url_format", "status": "pass", "message": "URL format is valid." },
    { "check": "ssl", "status": "pass", "message": "URL uses HTTPS." },
    { "check": "resolution", "status": "pass", "message": "Destination responded with 200.", "details": { "status_code": 200, "response_time_ms": 287 } },
    { "check": "redirects", "status": "pass", "message": "No redirects detected." },
    { "check": "response_time", "status": "pass", "message": "Response time: 287ms.", "details": { "response_time_ms": 287 } }
  ],
  "status_code": 200,
  "response_time_ms": 287,
  "validated_at": "2026-07-03T10:01:15.000Z"
}

A valid: true result means the destination URL resolves correctly and query parameters survive to the final page load. If valid is false, the checks array pinpoints the failing hop. The most common failure modes for Webgains programmes are e-commerce platform canonical URL enforcements on deep-linked product pages, trailing-slash normalization redirects, and HTTPS upgrade redirects that were not configured to preserve query strings. For a detailed walkthrough of diagnosing redirect chain failures, see how to check if a redirect strips UTM parameters.

Webgains UTM tracking gotchas for advertisers

Configure UTM parameters on the destination URL, not on the Webgains publisher link

Webgains generates publisher-facing tracking links in a format controlled by the platform. As an advertiser, you do not directly control the structure of the publisher link. The configuration point you own is the Destination URL or Default Landing Page in the Webgains Advertiser Hub for your programme. Paste the UTM-tagged URL generated by mlz build there. When a publisher’s Webgains link is clicked, the network routes through clicks.webgains.com and forwards to your configured destination URL, delivering the UTM parameters to your landing page.

Deep-linked product pages may have different redirect behavior than the programme landing page

Webgains supports deep links, allowing publishers to link directly to specific product or category pages rather than the default programme destination. Deep-linked pages on your site often have different URL handling: Magento enforces canonical URLs that can trigger an additional redirect, Shopify normalizes trailing slashes, and WooCommerce may redirect product slugs to the canonical product URL. Any of these platform-level redirects can strip query parameters if not configured to preserve the query string. Run mlz check against representative product-page deep link URLs before enabling them in your Webgains programme, not just against the main landing page.

Magento canonical URL enforcement strips query parameters from product pages

Magento 2 has a configuration option that enforces canonical URLs by redirecting requests for product URLs with query strings to the canonical product URL without those query strings. This is intended to prevent duplicate content indexing, but it also strips UTM parameters from deep-linked product pages in Webgains programmes. The Magento admin setting “Use Canonical Link Meta Tag for Products” controls whether this redirect is applied. If you are using Magento and deep links in Webgains, test the exact product page URLs with mlz check and confirm valid: true and no query-stripping redirects before activating deep link functionality.

Shopify trailing-slash redirect can strip query parameters on some store configurations

Shopify enforces canonical URL formats and may redirect requests that include trailing slashes or non-canonical product URL formats. On some Shopify store configurations, this redirect does not forward the original query string, stripping UTM parameters before GA4 fires. Validate the exact Shopify product page URLs you intend to use as Webgains deep link destinations using mlz check before entering them into the Webgains Advertiser Hub.

Casing inconsistency across programme configurations fragments GA4 reporting

Advertisers running multiple Webgains programmes across different markets or categories sometimes introduce casing variations: utm_source=Webgains in one programme and utm_source=webgains in another. GA4 is case-sensitive and records these as separate sources, making cross-programme affiliate attribution impossible. mlz build automatically lowercases all input values and replaces spaces with hyphens, producing consistent output regardless of the input. For the full explanation of GA4 case sensitivity, see are UTM parameters case sensitive in GA4?

Frequently asked questions

Where do I add UTM parameters in the Webgains Advertiser Hub?

In the Webgains Advertiser Hub, navigate to your programme settings and find the Destination URL or Default Landing Page field. This is where you paste the UTM-tagged URL generated by mlz build. The URL format is: https://shop.example.com/landing?utm_source=webgains&utm_medium=affiliate&utm_campaign=summer-sale-2026. Webgains will use this as the final destination when routing publisher clicks through its tracking redirect. For programmes with multiple creatives or seasonal landing pages, configure distinct UTM-tagged destination URLs for each. For deep link functionality, publishers create their own links directly to product pages on your site — validate those product page URLs independently with mlz check.

Does the Webgains clicks.webgains.com redirect strip UTM parameters?

Webgains’s clicks.webgains.com redirect is designed to forward the advertiser-configured destination URL intact, including all query parameters. Parameter stripping typically occurs on the advertiser’s server side after Webgains delivers the visitor: e-commerce platform canonical URL enforcement, trailing-slash normalization, or HTTPS upgrade redirects that do not preserve query strings. Run mlz check against your destination URL to confirm parameters survive the full chain to the final page load before activating your Webgains programme.

What utm_source value should I use for Webgains traffic?

Use utm_source=webgains as the baseline for all Webgains network traffic. Keep the value lowercase and hyphenated — mlz build enforces this automatically. Set utm_medium=affiliate consistently across all affiliate network traffic so GA4’s default channel grouping correctly identifies the Affiliate channel. If you want to segment by publisher type within Webgains (e.g. cashback vs. content vs. CSS affiliates), use utm_content for that segmentation rather than varying the source value.

How do I track performance across Webgains deep links in GA4?

For deep links to product and category pages, use utm_content to identify the page category: utm_content=womens-footwear, utm_content=mens-apparel. Keep utm_source=webgains and utm_medium=affiliate consistent across all deep links so GA4 aggregates all Webgains affiliate traffic in the Affiliate channel report. Generate each deep-link destination URL with mlz build and validate the product-page URL with mlz check before sharing it with Webgains publishers — platform redirects on product pages behave differently from the main programme landing page and must be tested separately.

Should I validate Webgains destination URLs in an automated pipeline?

For programmes with a high volume of deep-linked product pages or multiple active campaigns, automated validation is a practical safeguard. Use mlz check in a script that tests each destination URL before it is entered into the Webgains Advertiser Hub, failing the submission if any URL returns valid: false. This prevents e-commerce platform upgrades, Magento configuration changes, or Shopify theme updates from silently breaking affiliate attribution. For a complete implementation guide including GitHub Actions workflow templates, see automating campaign link validation in CI/CD.