Tracking performance in paid media is becoming more challenging, especially when the customer journey isn’t a straight line.
If your audience takes weeks or months to convert, uses multiple devices, or involves offline steps like procurement or phone calls, traditional tracking methods won’t give you the full picture.
Today, we’ll break down how to approach tracking when you’re dealing with complex journeys, so you can still measure success and improve campaign performance – even when full attribution isn’t possible.
Why standard conversion tracking falls short
Most out-of-the-box tracking tools are built for simple journeys: a user clicks an ad, then buys something or fills out a form. But in 2025, even these straightforward paths are disrupted by things like Apple’s ITP and browser privacy updates, third-party cookie deprecation, and the widespread use of ad blockers.
Now layer on a more complex customer journey, one with long research periods, multiple stakeholders, or offline purchasing, and it becomes clear why standard tracking isn’t enough.
Start with the customer journey
Before you touch any tracking setup, you need to understand how people actually buy from your business. That means identifying who’s involved, how long the decision takes, and which touchpoints play a role.
A few real-world examples:
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Home services: 90% of jobs are emergency-driven, with 80% of bookings made over the phone.
In this example, tracking phone calls, and their outcomes is critical. Not something provided out-of-the box by most analytics tools. -
Engagement rings: 95% of purchases are made by men, but 75% of research is done by women.
In this example, most web visits from women don’t end in a purchase, but clearly there is value in these journeys if their partner buys as a result. -
Life sciences: 95% of journeys start with a lab scientist, but 80% of purchases are completed by procurement via phone or email.
Tracking the journey between lab scientist and procurement is almost impossible, therefore not worth the energy. Focus on proxies instead.
Once you understand the path to purchase, you can decide what’s realistic to track, and what isn’t.
Tracking complex journeys: Two common scenarios
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When more than 50% of purchases are trackable
If over half of your conversions can be reliably tracked, focus on the outcomes that matter.
What to do- Optimise for final conversions: Use tracked purchase or lead data to inform bidding strategies.
- Join the dots: Use click IDs and CRM data to stitch together cross-device and cross-channel journeys.
- Feed the algorithm: Give platforms like Google Ads and Meta high-quality conversion data so they can optimise more effectively.
Why it matters
When a significant proportion of conversions are visible, you can confidently attribute performance and reinvest in the tactics that work. -
When less than 50% of purchases Are trackable
In cases where the majority of purchases happen offline or through fragmented journeys, tracking the final outcome won’t tell the full story.
What to do instead- Avoid over-reliance on end conversions: Final purchases may not reflect campaign impact if they occur outside of your tracking scope.
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Use proxy metrics:
- Micro-conversions like downloads, quote requests, or time on site
- Propensity modelling to identify users likely to convert based on historical data
- Sales or CRM feedback to add qualitative insight into what’s working
Why it matters
By using alternative signals, you can still guide campaign optimisation, even when end-to-end tracking is incomplete.
Core tracking techniques that support complex journeys
Client-side (browser-based) tracking
Useful when journeys stay online and are relatively straightforward.
What it tracks:
- Pageviews
- Clicks
- Form submissions
- On-site engagement
Tools: Google Tag Manager, Meta Pixel, LinkedIn Insight Tag
Limitations: Can be blocked by privacy settings and ad blockers
Server-to-server tracking
More resilient and accurate for fragmented or cross-device journeys.
How it works:
- Uses identifiers like GCLID, FBCLID, email or phone numbers
- Reduces reliance on browser-based tracking
- Enables stitching of data across channels and touchpoints
Best suited for: Businesses with long journeys, offline purchases, or multiple decision-makers.
Server-side Google Tag Manager (GTM)
Adds a layer of control and reliability to both tracking approaches.
Benefits:
- Improves data accuracy
- Reduces loss from browser restrictions
- Acts as a central hub for collecting and forwarding data to ad platforms
- Enhances data privacy and compliance
Key takeaways
- Understand the customer journey first: Tracking should be based on how people actually buy, not how platforms expect them to.
- Match your tracking strategy to what’s possible: Optimise around final conversions where you can, and use proxies where you can’t.
- Use server-side solutions to improve data quality: Especially important for cross-device journeys or offline conversions.
Getting tracking right in a complex environment isn’t about achieving perfection, it’s about building the clearest possible picture and using that to make informed strategic decisions.
