Conversion tracking is the backbone of any successful digital marketing campaign. Accurately tracking conversions can significantly influence your strategy and budget allocation. One highly effective method to enhance your conversion tracking accuracy is through cookie-based tracking using Google Tag Manager (GTM). In this detailed guide, we'll explore the why and how of implementing this method to elevate your marketing efforts.
Before diving into the step-by-step process, it's crucial to understand the importance of accurate conversion tracking and how it can impact your marketing campaigns. One of the main challenges in conversion tracking is avoiding duplicate conversions. Relying solely on form submission events can lead to inaccurate data due to duplicate entries. Users might refresh the thank you page or accidentally resubmit the form, causing multiple conversions to be recorded. Using cookies ensures that each conversion is tracked only once within a specified timeframe, providing a more accurate measure of your campaign’s success.
Another issue is filtering out non-human interactions. Bots and automated scripts can trigger form submissions, leading to skewed conversion data. Implementing a cookie-based approach adds an extra layer of verification, helping to filter out non-human interactions and improve the quality of your data. This method also supports session-based tracking, tying conversion tracking to a specific user session through cookies. This allows you to distinguish between multiple conversions by the same user across different sessions, ensuring that each session’s conversions are tracked accurately and reflecting true user behavior.
Improved attribution accuracy is another significant benefit. With multiple forms across different landing pages, attributing conversions accurately can be challenging. Setting a cookie when the landing page loads and checking it on the thank you page helps to more precisely attribute conversions to the correct landing page and marketing campaign. Additionally, conversion inflation, which occurs when the same user is counted multiple times as a conversion within a short period, can be mitigated by the cookie-based approach. This method ensures that a conversion is only counted if the cookie is present, providing a more realistic measure of your campaign’s performance.
Managing cookies and their expiration aligns your tracking practices with privacy regulations (like GDPR and CCPA). Setting cookies with clear expiration times and using them only for session-based tracking makes your tracking practices more transparent and compliant.
Now, let’s dive into the detailed process of setting up cookie-based conversion tracking using Google Tag Manager.
The first step is to set a cookie when the landing page loads. This can be achieved by inserting a small piece of JavaScript code into the HTML of your landing page. Alternatively, you can do this directly through GTM. Here’s the script you can use:
<script>
// Set a cookie named "conversionCookie" with a value of "true"
// The cookie will expire in 1800 seconds (30 minutes)
// The "path=/" ensures the cookie is accessible throughout the site
document.cookie = "conversionCookie=true; max-age=1800; path=/";
</script>
You can implement this script through Google Tag Manager by navigating to your GTM container, creating a new tag, and selecting "Custom HTML" as the tag configuration. Paste the script into the HTML field, set the trigger to fire on the landing page(s) where you want to set the cookie, and then save and publish your container.
Next, you need to check if the cookie exists when the thank you page loads, delete it, and push a custom event to the dataLayer. This ensures that the conversion is only counted if the user lands on the thank you page with the cookie present, verifying the legitimacy of the conversion. Here’s the script for this step:
<script>
// Function to retrieve the value of a specified cookie
function getCookie(name) {
// Split the document.cookie string into individual cookie pairs
let cookieArr = document.cookie.split(";");
// Loop through the array of cookie pairs
for(let i = 0; i < cookieArr.length; i++) {
// Split each cookie pair into name and value
let cookiePair = cookieArr[i].split("=");
// Check if the cookie name matches the specified name
if(name == cookiePair[0].trim()) {
// Return the decoded value of the cookie
return decodeURIComponent(cookiePair[1]);
}
}
// Return null if the cookie is not found
return null;
}
// Check if the "conversionCookie" is present
if (getCookie("conversionCookie")) {
// Push a custom event to the dataLayer if the cookie exists
window.dataLayer = window.dataLayer || [];
window.dataLayer.push({
'event': 'conversionDetected'
});
// Delete the "conversionCookie" by setting its expiration date to a past date
document.cookie = "conversionCookie=; expires=Thu, 01 Jan 1970 00:00:00 UTC; path=/;";
}
</script>Similarly, implement this script through Google Tag Manager by creating a new tag, selecting "Custom HTML," pasting the script into the HTML field, setting the trigger to fire on the thank you page(s), and then saving and publishing your container.
Once the cookie setting and checking scripts are in place, you need to configure GTM to listen for the custom event pushed to the dataLayer and use it to trigger your conversion tracking tags. Start by creating a trigger for the custom event. Navigate to "Triggers" in your GTM container, create a new trigger, name it appropriately (e.g., "Conversion Detected Trigger"), choose "Custom Event" as the trigger configuration, and set the event name to conversionDetected. Save the trigger.
Next, create a tag for the conversion event. Navigate to "Tags," create a new tag, name it (e.g., "Google Ads Conversion Tag"), choose "Google Ads Conversion Tracking" as the tag configuration, and enter your Conversion ID and Conversion Label provided by Google Ads. Set the trigger to the "Conversion Detected Trigger" you created earlier, then save and publish your container.
Let’s revisit why this method is so beneficial, expanding on the initial points. Accurate conversion tracking is crucial. By tying conversion events to a specific user session with a cookie, you avoid the pitfalls of duplicate conversions. This ensures that your data accurately reflects user behavior, providing a clearer picture of your campaign's effectiveness. Filtering out non-human interactions and duplicate submissions improves the overall quality of your data. This leads to more informed decision-making, as your conversion data better represents actual user interactions with your site.
Session-based tracking provides insights into user behavior over a specific session, allowing for a deeper understanding of how users interact with your site. This can inform future marketing strategies and website optimizations. Accurate attribution of conversions to the correct landing page and marketing campaign is crucial. This method ensures that conversions are correctly attributed, allowing you to assess the performance of individual campaigns more effectively. By setting cookies with clear expiration times and using them for session-based tracking, you can align your practices with privacy regulations like GDPR and CCPA. This makes your tracking methods more transparent and compliant.
Let’s walk through a practical example of how this method can be implemented and the impact it can have. Imagine you run a digital marketing campaign promoting a new product through multiple landing pages. Each landing page has a form that users fill out to express interest in the product. You want to track conversions accurately and ensure that each user’s submission is only counted once.
To implement this, start by adding the cookie-setting script to all your landing pages. This script will set a cookie when a user lands on the page. Next, add the cookie-checking and deletion script to all your thank you pages. This script will check if the cookie is present when a user reaches the thank you page, push a custom event to the dataLayer, and delete the cookie. Finally, configure Google Tag Manager by creating triggers and tags to listen for the custom event and fire conversion tracking tags accordingly.
Once your cookie-based conversion tracking is set up, it’s important to test and optimize it to ensure it’s working correctly. Start by testing the cookie setting and checking scripts to make sure they are functioning as expected. Use your browser’s developer tools to verify that the cookie is being set on the landing page and deleted on the thank you page. Check the dataLayer to ensure the custom event is being pushed correctly.
Next, test the triggers and tags in Google Tag Manager. Use GTM’s preview mode to verify that the conversion tracking tag fires when the custom event is detected. Make sure the conversion is recorded in Google Ads or your other tracking tools. Finally, monitor your conversion data to ensure it accurately reflects user behavior. Look for any anomalies or discrepancies that might indicate issues with the tracking setup. Continuously optimize your tracking by making necessary adjustments based on your observations and testing results.
Implementing cookie-based conversion tracking using Google Tag Manager is a powerful way to enhance the accuracy and reliability of your conversion data. By setting cookies on landing pages and checking them on thank you pages, you can avoid duplicate conversions, filter out non-human interactions, and ensure accurate session-based tracking. This method also improves attribution accuracy, prevents conversion inflation, and aligns with privacy regulations. Following the steps outlined in this guide, you can set up and optimize cookie-based conversion tracking to gain deeper insights into your campaign performance and make more informed marketing decisions.
By mastering this technique, you'll be able to track conversions more accurately, enhance the quality of your data, and ultimately improve the effectiveness of your marketing efforts. So, get started with implementing cookie-based conversion tracking today