Campaign attribution troubleshooting

This page covers troubleshooting for campaign attribution issues. For general web analytics troubleshooting, see the main troubleshooting page. If you're using Marketing Analytics to tie ad spend to conversions, the same attribution mechanics apply – campaigns are matched to your conversion events via utm_campaign and utm_source.

Have a question? Ask PostHog AI

Why are my UTMs showing on pageviews but not on conversions?

If you see UTM parameters on $pageview events but conversions aren't attributed correctly, the issue is almost always identity fragmentation – not a UTM capture problem.

For campaign attribution to work, the user's person profile must stay connected from landing to conversion. A person profile is PostHog's representation of a user, identified by a distinct_id. Here's the typical flow:

1. User lands with UTMs
2. PostHog captures UTMs on $pageview
3. A distinct_id is generated
4. User converts (e.g., signed_up)
5. identify() is called
6. All prior events with that same distinct_id get stitched to the person

If the distinct_id changes at any point before conversion, attribution breaks.

Why does the distinct_id change?

The distinct_id can change when:

• Storage is cleared or isolated – Browsers like Safari aggressively clear cookies and localStorage, especially for third-party contexts
• Users switch browsers or devices – Each browser/device gets a new anonymous distinct_id
• In-app browsers are involved – Apps like LinkedIn, Instagram, and Facebook use embedded webviews with isolated storage
• Persistence is set to memory – Without persistent storage, every page load creates a new identity
• PostHog reinitializes – Multi-app architectures or SSR apps may create duplicate PostHog instances

When any of these happen before identify() is called, the original distinct_id (with the UTM data) becomes orphaned from the conversion event.

How do I check if this is happening?

Run this SQL query to compare landing and conversion events:

select
    event,
    properties.utm_source,
    properties.utm_campaign,
    distinct_id,
    person_id
from events
where timestamp >= today() - 7
and properties.utm_source = 'linkedin' -- replace with your utm_source
order by timestamp desc
limit 100

If you see different distinct_id or person_id values for pageviews and conversions from the same user, you have identity fragmentation.

Why are users from LinkedIn/Meta ads not being attributed?

This is a common issue when running ads on social media platforms that open links in their native in-app browsers. Here's a typical scenario:

1. A user sees your ad in the LinkedIn mobile app
2. They tap the link, which opens in LinkedIn's in-app browser (webview)
3. PostHog captures the $pageview with UTM parameters and assigns a distinct_id
4. The user decides to sign up but prefers using their main browser
5. They tap "Open in Safari" or navigate to your site directly
6. A new distinct_id is created because Safari doesn't share storage with LinkedIn's webview
7. The conversion event is now tied to a different person profile than the original pageview

In-app browsers (LinkedIn webview, Meta webview, Instagram) cause attribution issues because:

• Storage is isolated from the system browser
• Cookies aren't shared when users switch to their main browser
• The distinct_id resets on navigation
• App-to-browser handoffs reset storage

You can detect this by checking user agents containing linkedin, fbav, or instagram. If a large share of your traffic comes from these sources, expect higher identity fragmentation.

The best fix depends on your specific situation, but it usually involves propagating UTMs or the distinct_id/session ID as much as possible:

1. Pass UTM parameters through your signup flow (e.g., in hidden form fields or URL parameters)
2. Identify users as early as possible in the funnel
3. Use cross-domain tracking if you have separate marketing and app domains

If UTMs and identity look fine but campaigns still don't match in Marketing Analytics, the problem may be a naming mismatch instead: your utm_campaign or utm_source values don't match what the ad platform reports. Fix this with UTM campaign manual mappings and custom source mappings – for example, mapping utm_campaign=summer-promo to the campaign named "Summer Sale 2025", or attributing utm_source=fb to Meta Ads.

Why does attribution break when users navigate between pages?

This typically happens when the storage is disconnected on navigation:

1. Persistence is set to memory

If persistence: "memory" is configured (common when cookie consent isn't granted), each page load creates a new distinct_id. Check your config:

posthog.init("key", {
  persistence: "localStorage+cookie" // Recommended
})

2. PostHog is reset

PostHog may reinitialize without preserving the distinct_id if:

• Your landing page and signup page reload the entire app
• You're using SSR apps or multi-app architectures
• You have separate marketing and app codebases
• You're using two different PostHog instances (e.g., different project tokens for marketing vs app)

Ensure PostHog initializes once and the distinct_id persists across pages.

3. Subdomain mismatch

If your marketing site is at marketing.example.com and your app is at app.example.com, cookies must be configured at the root domain level. See cross-domain tracking for setup instructions.

Why do ad platform clicks not match my attributed conversions?

Ad platforms often count interactions that aren't website visits:

• Likes, shares, and comments
• Profile clicks
• Video views
• Carousel swipes

Not all "clicks" result in a pageview. Expect discrepancies between platform metrics and UTM-based attribution.

Ad platforms also attribute conversions using their own pixel data and attribution windows (e.g., 7-day click, 1-day view), which differ from PostHog's event-based attribution. This is why Marketing Analytics shows both reported conversions (from the ad platform) and PostHog conversion goals side by side – see reported vs PostHog conversions for a full explanation.

Why is mobile attribution worse than desktop?

Modern iOS and mobile browsers have privacy restrictions that affect tracking:

• Restricted cookie lifetime
• Isolated webview storage
• Session storage resets
• Intelligent Tracking Prevention (ITP)

This disproportionately impacts mobile campaign attribution. Cross-device attribution also fails when:

1. User clicks ad on mobile
2. Browses anonymously
3. Signs up later on desktop

Unless you explicitly connect those identities with identify(), the mobile pageviews remain separate from the desktop conversion.

How do I debug identity fragmentation?

Run this query to find cases where the same device has multiple persons:

select
    properties.$ip,
    properties.$raw_user_agent,
    uniq(person_id) as persons,
    uniq(distinct_id) as distinct_ids
from events
where timestamp >= today() - 30
and properties.utm_source = 'linkedin' -- replace with your utm_source
group by properties.$ip, properties.$raw_user_agent
having persons > 1
limit 100

If persons > 1 for the same IP and user agent, you have likely found identity fragmentation. Note that IP and user agent matching is not a guaranteed fingerprint – multiple users can share the same IP (e.g., office networks, VPNs) and user agent combination. However, it's a useful approximation for detecting fragmentation patterns.

You can also compare conversion IPs to ad click IPs. If you see conversions from the same IP/user agent as your ad clicks, the traffic is arriving – it's just not being stitched to the right person.

How do I fix attribution issues?

1. Ensure persistence is not memory

posthog.init("key", {
  persistence: "localStorage+cookie"
})

2. Identify users early

Call identify() as early as possible in the funnel to reduce anonymous navigation.

3. Bootstrap across domains

If you have multiple domains or apps, pass distinct_id and session_id explicitly. See cross-domain tracking.

4. Minimize page reloads

Keep users in a single-page flow before conversion when possible.

When should I raise a support ticket?

Raise a support ticket if:

• UTMs are present on pageviews
• distinct_id changes unexpectedly
• Identity stitching appears broken despite correct persistence config
• In-app browser flows consistently fragment identity
• Subdomain configuration is correct but still failing

Include:

• Example distinct_id(s) and person_id(s)
• User agent
• Campaign name
• Your persistence config
• Your domain structure

Raise a support ticket here.

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