Performance marketers can track almost everything online. Clicks, impressions, form fills, even scroll depth. But the moment a prospect decides, “I’ll just call,” a lot of that visibility disappears.
Dynamic Number Insertion (DNI) is how you get that visibility back.
DNI turns phone calls into properly attributed conversions, so you can see exactly which channel, campaign, ad or even keyword made the phone ring. And the good bit? With Delacon, it’s quick to roll out, works in real time, and doesn’t require you to rebuild your website.
What is Dynamic Number Insertion?
DNI is a call tracking feature that automatically swaps the phone number on your website based on how a visitor arrived.
- Someone comes from Google Ads → they see tracking number A
- Someone comes from organic search → they see tracking number B
- Someone comes from Facebook → they see tracking number C
All three numbers still ring your business as normal, but behind the scenes Delacon records the source for every call.
It’s session-based too. That means five people can land on your site from five different channels at the same time and all five calls will be attributed correctly. No guessing. No “How did you hear about us?” at the call centre.
How DNI Works (without the tech headache)
- A small script is added to your site (often via Google Tag Manager).
- When a visitor arrives, the script checks where they came from.
- It dynamically replaces your usual phone number with the right tracking number.
- If they call, Delacon logs the source, campaign, keyword and page.
- When they leave, that tracking number goes back into the pool.
No hard-coding dozens of numbers, no separate landing pages for every ad group. One snippet, automated number swapping.
Why Tracking Calls Matters More Than You Think
A lot of businesses still judge campaign success on form fills alone. The problem is that in many industries — finance, healthcare, travel, home services, higher ed — the best leads still pick up the phone.
- Callers are usually more ready to buy
- Phone calls convert 10–15x better than web leads in some sectors
- A big chunk of paid traffic ends up calling instead of filling in a form
If you don’t track those calls, you can end up turning off a campaign that’s actually working simply because the value is coming in by phone instead of a web form.
DNI fixes that by treating calls as first-class conversions.
What You Get From DNI
1. Complete marketing attribution
See which channels, ads and keywords drive calls, not just clicks. Calls become part of your real conversion numbers.
2. Lower CPA
Once calls are counted, a lot of campaigns instantly look more efficient. Then you can cut spend on channels that don’t produce calls and put more into the ones that do.
3. Higher conversion rates
Calls tend to be higher intent. When you know which campaigns produce more of them, you can optimise to get more of those high-value leads.
4. Smarter budget decisions
DNI is basically “UTM for phone calls”. You can finally tell the difference between a channel that sends traffic and a channel that sends customers.
5. Better customer experience
Because you know where the call came from, you can route it better (for example, to the right team or location).
Why Delacon’s DNI Is Easier
A lot of marketers hear “dynamic number insertion” and think “this will be a dev project”. With Delacon it doesn’t have to be.
- Single script deployment (often via GTM)
- Real-time source matching (Google, Meta, Bing, email, directories, affiliates, you name it)
- Supports multiple simultaneous visitors seeing different numbers
- Pushes call data into your existing stack (GA4, Google Ads, Salesforce, HubSpot, Looker Studio, Power BI)
- Secure and reliable (built on Delacon’s call tracking platform)
So you get enterprise-level attribution without having to hand your website over to a developer every time you launch a new campaign.
Who Should Be Using DNI?
- Agencies who need to prove ROI across multiple clients and stop reporting “partial” results
- Performance marketers who optimise to CPL/CPA and need the full dataset
- Multi-location and franchise brands that need to know which campaigns drive calls into which locations
- Industries where people still call (travel, healthcare, financial services, education, home services)
If calls are part of your funnel, DNI should be part of your tracking.
Why agencies choose Dynamic Numbers?
- Faster ROI proof: With calls tying back to the exact channel, campaign, or keyword that drove it, you can expect to see up to a 33% improvement in lead conversion rate.
- Multi-client control: Standardise attribution across your entire portfolio with clean separation by client and roll-up views for directors, with up to a 67% decrease in CPA while maintaining the same sales volume
- Accuracy that scales: Businesses using session-based call tracking have seen up to a 36% reduction in marketing spend – saving tens of thousands of dollars per month.
*Note: Results are based on Delacon case study with Jaywing and Mobile Tyre Shop.
Wrap-up
Dynamic Number Insertion closes the biggest attribution gap most marketers still have: phone calls.
By dynamically showing the right number to the right visitor and logging every call back to source, DNI lets you:
- See the true value of your paid and organic campaigns
- Improve conversion and reduce CPA
- Spend more on what works and less on what doesn’t
Delacon’s DNI makes that possible with minimal setup and real-time data. Add the script, start running campaigns, and finally see which activity is actually making the phone ring.
👉 Want to see how DNI would work on your site?