Dynamic Number Insertion (DNI)

Dynamic Number Insertion (DNI) closes the attribution loop between online advertising and offline phone calls. Here's the problem it solves: A user searches 'plumber near me', clicks your Google Ads ad, lands on your website, sees a phone number, and calls. But your analytics system never connects that call to the keyword, the ad, or the campaign that drove it. The call happens offline, outside of Google's tracking.

DNI fixes this with a JavaScript snippet on your website that swaps the displayed phone number for each visitor. When Visitor A (who came from a Google Ads click) lands, they see tracking number +1-555-001-0001. When Visitor B (who came from organic search) lands, they see +1-555-001-0002. When A calls, you know exactly which keyword and campaign generated it. When B calls, you know they came from organic search.

The attribution data DNI captures includes GCLID (Google's click ID for desktop traffic), gbraid (Google's click ID for iOS app-bound traffic), and wbraid (Google's click ID for iOS web traffic). This is critical for iOS users where cookie consent often prevents normal tracking. Even if an iPhone user declines cookies, CallMatrix can still capture their gbraid from the landing page URL and attribute the subsequent call back to the exact Google Ads keyword.

DNI also captures UTM parameters, landing page URL, referrer, and IP address. All of this flows into your DNI pool configuration, which you can segment by vertical, region, or campaign. A single page can run multiple DNI snippets (via namespaced window.CallMatrix[campaignId] API) so different CTAs on the same page route to different buyer clients with separate tracking pools.

Session stickiness ensures the same visitor sees the same number across page views (default 20-minute window). After the session expires, the number returns to the pool for the next visitor.