How to track affiliate referrals from external websites

Write down the full path a visitor will take: affiliate link, external website, product or landing page, checkout, and confirmation. Decide which WordPress site records the conversion. The affiliate system only needs to be installed on that primary site when the external site is being used as a marketing or landing site.

If the affiliate link points straight to your store, use the normal referral URL, such as https://store.example/?ref=123. If the visitor lands on another domain first, the affiliate ID must be carried from that domain to the store. A normal cross-domain cookie will not do this by itself.

For a manual setup, give each affiliate a landing URL containing an identifier, such as https://promo.example/?ref=123. On the external site, preserve that value in a first-party cookie or server-side session, then append it to every button or link that sends the visitor to the main WordPress site.

The main site must receive the identifier in the format its affiliate system accepts, usually a query parameter such as ?ref=123. This route is fine for a small number of campaigns, but you must maintain the code, preserve the parameter through redirects, and check that caching, consent tools, and URL builders do not remove it.

If you use AffiliateWP’s External Referral Links add-on, install AffiliateWP on the primary conversion site and install the add-on on the external WordPress site. In the external site’s settings, enter the exact URL of the site where AffiliateWP is installed, including the correct HTTP or HTTPS protocol, then set the cookie expiry period and save the changes.

The add-on uses non-pretty referral URLs such as /?ref=123 or /?ref=john. Pretty links are not supported by this setup. Visits are recorded when the visitor reaches the primary site, not while they are browsing the external site.

Use the affiliate ID or username in each referral URL, then place the URL on the external site’s buttons, banners, articles, and calls to action. Check every destination, especially links that go to a product page, cart, or checkout rather than the home page.

If you need affiliates to generate their own links, AffiliateWP can output a referral URL for a chosen page using its referral URL shortcode. That is useful when each affiliate needs a different tracking value while promoting the same external campaign page.

Open an affiliate link in a private browser window or on a separate device. Confirm that the external page loads, the onward link still contains the affiliate value, and the primary site records the visit or referral cookie. Complete a low-value test order and check the referrals screen after the integration processes it.

Do not test by typing the store URL directly after visiting the external page. Also check the failure cases: a redirect that strips ?ref=, a different HTTP and HTTPS protocol, a cached page with an old link, rejected cookies, and a customer switching browsers. Affiliate tracking normally depends on the browser retaining its tracking cookie.

For a working WordPress-to-WordPress setup, AffiliateWP with its External Referral Links add-on is the faster option. It handles the external-site referral cookie and passes the affiliate ID to the primary site, so you do not have to maintain custom URL and redirect code. Use the manual route when you only have a simple campaign and are comfortable maintaining it; use the add-on when several affiliates, pages, or external sites are involved.

Remember its limits: AffiliateWP only needs to run on the main conversion site, the external site needs the add-on, non-pretty referral URLs are required, and visits are recorded on the primary site rather than the external site.