The problem
For a contractor, a cleaner or a restoration company, most leads arrive by phone. Web analytics is built around clicks; so the majority of the business is the part analytics cannot see.
The usual consequence: form submissions get tracked, phone calls do not, and every channel that mainly drives calls looks like it produces nothing. Budgets get cut on that basis.
The common workaround makes it worse. Counting taps on a phone number as conversions treats a tap as a conversation. Someone can tap and hang up, or reach voicemail at 3am. If that counts as a lead, the bidding algorithm optimises toward producing more of it.
The approach
The phone number displayed on a page changes depending on how the visitor arrived. Someone from a Google Ads click sees a different number than someone from organic search or a direct visit. When the phone rings, the number dialled identifies the source.
That converts “this call probably came from the ads” into a fact.
What the platform handles:
- Number pools assigned per source
- Session-to-number mapping that survives the visit
- Call outcome, not just call attempt; a connected conversation is different from a ring-out
- Attribution written back to the analytics and CRM layer
- Numbers held in the client’s own account, so they port if the client leaves
Why build rather than resell
Control over correctness. Attribution is the thing we tell clients we get right. Owning the implementation means we can verify it rather than trusting a vendor’s dashboard.
No dependency in the middle of our core claim. If the measurement half of our positioning depends on someone else’s product, their roadmap becomes our roadmap.
It is the honest version of the pitch. We say we build systems. Building the one that underpins our most technical claim is the demonstration.
Implementation
Built as a Next.js application deployed on Vercel, with Drizzle as the data layer and Playwright covering the critical end-to-end flows. Delivery was phased and documented, and a production hardening pass was recorded before launch.
Concurrency behaviour was tested explicitly, which matters more here than it might sound. Attribution is a system where two events arriving in the same instant can corrupt the record; the same number reassigned to two sessions, or a call written to the wrong source. That is the class of bug that produces confidently wrong data, which is worse than no data.
What this proves
It is the reason we can talk about conversion tracking as engineering rather than as a service description. When we say a phone lead can be attributed like a form lead, this is the thing doing it.