23 September 2026 · 6 min read · Oscar Markham
How to know which ads actually made the phone ring
For most trades and service businesses the majority of enquiries arrive as phone calls, and the majority of phone calls are untracked. That means the reporting shows form submissions, the business knows the phone rang more, and nobody can connect the two. It is the single biggest measurement gap in small business advertising.
Why it matters more than it sounds
If half your enquiries are calls and you only count forms, your cost per lead looks twice as bad as it is. Campaigns get switched off for underperforming when they were working.
Worse, you cannot tell which campaign produced the calls, so budget gets moved toward whatever happens to generate forms rather than toward whatever generates business.
The simple methods, in order of effort
Ask. 'How did you hear about us' is imperfect, because people misremember, but it is free and it is better than nothing.
Use a distinct number in your advertising. A separate mobile or a second line used only on ads tells you exactly how many calls came from advertising, with no software at all.
- Ask every caller and log it — free, imperfect, still useful
- A dedicated number used only in ads — cheap and unambiguous
- Call tracking with dynamic number insertion — accurate, shows which campaign
- Click-to-call tracking in the ad platforms — free, catches mobile taps only
Dynamic number insertion
This swaps the number shown on your website depending on how the visitor arrived, so a call from a Google Ads visitor shows a different number from an organic one. It is the only method that attributes calls to specific campaigns reliably.
It costs a modest monthly fee and it is the right answer for a business spending meaningfully on ads. Below a few hundred euro a month it is probably not worth the complexity.
The GDPR position
Call recording is personal data processing and requires a lawful basis and, in practice, notification at the start of the call. Call tracking without recording is far simpler — you are recording that a call happened and from which source, not its content.
If you record calls, tell callers at the start, say why, and set a retention period. If you only need attribution, do not record; you do not need to and it avoids the whole question.
What to do with the answer
Once you can see which campaigns produce calls, the usual discovery is that one campaign is carrying the account and another has been quietly wasting money for months.
That single reallocation typically pays for the tracking many times over in the first quarter.
Written by Oscar Markham, founder of Dublin Growth Digital. We run lead generation for Irish estate agents and trades, reported every Friday in enquiries and booked work.