In services, real estate or B2B, deals often close by phone, not with a button on the website. If you don't measure the call, advertising can't see part of its best result. Here's how call tracking and server-side work together.
What call tracking is
Call tracking connects a phone call to where the caller came from. Typically via Dynamic Number Insertion — a visitor from an ad sees a different phone number on the site, by which the call is attributed to its source. This part is usually handled by a dedicated call-tracking tool.
Where server-side comes in
A call is by nature an offline conversion — it happens off the website. Server-side tracking helps send that conversion back to advertising:
- Capturing the click ID. On arrival from an ad, the click identifier is stored with the visitor — see what GCLID and click IDs are.
- Connecting to the call. When the call-tracking tool reports a qualified call, it's linked to the stored click ID.
- Sending the conversion. The call (or the deal closed from it) is sent back to advertising as an offline conversion. The principle is in measuring offline conversions.
What to watch
- Measure qualified calls, not every pickup — otherwise you optimize for quantity.
- For high values, send the closed-deal value, not a flat figure.
- A phone number is personal data — handle it under GDPR.
Summary
Call tracking connects a call to its source; server-side helps send that conversion (and its value) back to advertising. For sectors that close by phone, that's the difference between measuring half the result and all of it. More in lead and B2B measurement.