The Marchex Blog

Attributing offline conversions by channel – A simple approach

Attributing offline conversions doesn’t have to be complex. In the age where data is more accessible than ever, it’s natural to seek increasingly more granular insights. But, to what end? At Marchex, we aim to avoid over-saturation–pursuing data for data’s sake—and instead, focus on data that’s actionable. So, how can we quickly attribute Google, referral, and Facebook offline conversions back to marketing spend without adding unnecessary complexity and cost?

The answer is with a simple: 1:1 dynamic number insertion. With this option, we can use one tracking line per media channel and set up a JavaScript re-write based on referring domain. In case you’re thinking a JavaScript re-write sounds complex, let me explain. JavaScript rewrites perform a simple task only when a specific condition is met. You can think of it as, “if a given condition occurs, then a pre-defined task is performed.” In the case of 1:1 dynamic number insertion, if the JavaScript snippet recognizes a specific referring domain, it will re-write the phone number displayed to the user, and you’ll know where they came from since the displayed number is assigned to a specific channel.

Paid Search

This is the most common channel that marketers want to attribute conversions to because the bulk of most marketers’ budget still goes to Google AdWords. An important consideration here is the level of complexity necessary to give you actionable insights. Some factors to consider are what percentage of conversions happen offline (over the phone) compared with online? Do you get enough offline conversions where the data would change your bidding strategy? If you suspect the answer is “no” to this second question, but you still want to get credit for those offline conversions then 1:1 dynamic number insertion is a perfect solution.


What kind of traffic is your SEO effort driving to your site? Do these visitors convert? Or are they just researching, price shopping or getting educated? By implementing a simple 1:1 dynamic number, you can track those organic customers if they make a phone call to your business. You can also learn what they called about and whether they converted.

Set up different CTNs for calls from SERP listings and calls from your landing page. That way, you have an even more accurate view.

Affinity Partners

Do you have partners that send you leads? How do you track those conversions? If a partner links to your website and sends traffic your way, how can you measure the value of that traffic? If a customer can click a link on a partner’s site and navigate to your website, any offline conversions resulting from those sessions can be flagged with 1:1 dynamic number insertion. Now, you can see which partners are driving quality traffic, and which partners are merely costing you money.


Are you advertising on Facebook? If customers can click a Facebook ad and reach your website, you should be using 1:1 dynamic number insertion. Yes, Facebook will tell you all about what happened online in Business Manager, but what about when these customers make a phone call from your site? The social network doesn’t have a way to bridge that gap, so it’s up to you to make sure you get credit for those Facebook offline conversions and attribute that back to your social campaign. With a call analytics provider that integrates with Facebook, you can create offline event sets to measure those conversions side-by-side.

In summary, it’s possible to get credit for 100% of offline conversions and gain actionable insights across all your marketing channels by using a few tracking lines and a bit of JavaScript code.

Interested in learning more? Check out our Call Analytics 101 guide.