What Is the Difference Between Tracking Pixel and S2S Postback URL Tracking?

One of the most crucial campaign-related choices you’ll make is how to go about conversion tracking in affiliate marketing. This decision can either help you optimize your campaigns faster or totally ruin all your efforts. Basically, you have two options: tracking pixel vs postback.

You’ve probably seen these terms, but what exactly do they mean? And how does each one work? We’ve compiled a quick summary and some information about these tracking methods: what’s the difference, which one is better, and when.

Key Takeaways:

• Pixel based tracking relies on browser cookies, making it vulnerable to privacy restrictions and user actions, and it’s also susceptible to inaccuracies and data loss.
• The S2S (server-to-server) postback URL tracking method does not depend on browser cookies. This makes it more accurate, secure, and resistant to data loss.
• When comparing pixel vs S2S, the latter offers flexible and transparent conversion tracking, even for complex user journeys.
• You can make the most of both methods by using RedTrack, which provides easy-to-set-up S2S integrations with over 200 platforms, including Facebook, Google, and Bing.

What Is a Tracking Pixel?

A tracking pixel (also called a web beacon) is a tiny, invisible image that you embed on your website, landing page, or email. It’s usually 1×1 pixel in size, which is why most people call it a 1×1 pixel tag.

The pixel is hosted on a server and is accessed via a tracking pixel URL, which serves as the endpoint that delivers the image. Despite its small size, it plays an important role in online advertising and analytics.

A pixel tracks how people respond to your web content, ads, or email. By quietly collecting user info in the background, it allows you to measure campaign performance, retarget a warm audience, and get better ad results.

Some information can be stored in cookies, which help identify users and attribute conversions to previous visits. When a conversion happens, cookies are often reviewed to authenticate it to an appropriate user session. Tracking pixels can track webpage visits, ad impressions, conversions, and a whole bunch of other metrics.

How Tracking Pixels Work

As we mentioned, a tracking pixel is an invisible image you insert into your web page or email to track user behavior. When someone opens the page or email, their browser sends a request to the tracking pixel URL and passes along information about their activities. This quietly records some visitor details like their IP address or browser type.

To illustrate how this happens, imagine that a Facebook user clicks on your ad and buys an item. As soon as they arrive at your “thank you” or “order confirmation” page, the tracking pixel fires.

Put simply, it fetches the invisible image and reports the visit and conversion back to your ad platform. Then, the platform attributes that conversion to the right campaign, so you know which ads are working.

What Are the Pros and Cons of the Tracking Pixel Method?

The great thing about pixels is that they are very easy to set up. Within just a few minutes, you can have your pixel up and running, and all you need to do is copy a chunk of code and paste it into your website. But it’s far from being a perfect tracking solution. Let’s take a look at the main benefits and downsides.

Pros of the Tracking Pixel Method

Tracking pixels offer a straightforward way to monitor user behavior, which is why marketers have stuck to them for so long. Here are its major benefits:

• Quick and easy implementation — the setup is very simple: your ad platform will give you a code snippet; just copy and paste it into the HTML of the web page where you want to track events, and you’re done.
• Real-time tracking — tracking pixels give you real-time conversion data, so, if you’re tracking open rates or clicks, it logs those actions in the moment they occur. Then, you can make timely marketing decisions with this data.
• Cost-effectiveness — they are either free or extremely affordable to use, even if you’re tracking multiple different conversions, it’s not going to put a dent in your wallet.
• Multiple touchpoint flexibility — you can use tracking pixels across different customer touchpoints, including email, social media ads, and your website.

Cons of the Tracking Pixel Method

Yes, they are cheap, convenient, and easy to use, which makes them good for your budget. But they also fail easily, and here’s why:

• Unreliable data collection — tracking pixels depend on the user’s browser to gather data, so if the user disables cookies, deletes them, or clears their cache, you’ll miss out on a lot of conversation data or will have to deal with inaccurate data.
• Browser and user restrictions — while most browsers block third-party cookies by default, some users also install ad blockers, which stop pixels and cookies from loading on a page and thus prevent analytics platforms from firing, giving you incomplete data.
• Privacy concerns — pixels track data in the background, sometimes without the user’s consent. This is an ethically murky territory and could mean violating GDPR, CCPA, or some other privacy laws, which can be solved by applying privacy-first tracking methods.

What Is a Postback URL?

Let’s start with the basics: what is postback URL tracking, and how does it relate to server-to-server (S2S) tracking?

According to the postback URL meaning, it is a unique URL that allows a traffic source (like an ad network or affiliate platform) to send data about conversions or user actions back to an ad tracking platform. This data exchange doesn’t involve the user’s browser. Instead, it happens on the server side.

What can it look like? Here’s a postback URL example:

• https://yourwebdomain.com/postback?cid={click_id}&payout={payout}&txid={transaction_id}

Mind, though, that a Facebook postback URL uses a slightly different structure: it starts with Facebook’s Graph API URL, followed by your Pixel ID and access token as a query parameter. Similarly, a Google Ads postback URL starts with your endpoint (where Google expects to receive the conversion data) followed by parameters like the Google Click Identifier (GCLID), conversion value, and currency. You can learn more about that here.

The postback URL approach ties directly into S2S tracking, where data is exchanged between servers. S2S is a more nuanced but better way of getting information about users and what they clicked on. This method generates a click ID value via an HTTP request that is used for tracking. Once a conversion happens, the affiliate network sends the value and info to your ad tracking software, like RedTrack, and gives you detailed information about everything.

How Does S2S Postback Tracking Work?

While postback S2S has the same goal as tracking pixels, the methods are different. Here’s how it works:

1. A user sees an ad and clicks on it.
2. Your tracking platform captures the click and assigns a unique click ID, then forwards the user to your landing page.
3. The user then makes a purchase, signs up, or completes some other conversion event.
4. Your advertiser’s server captures the conversion data along with the initial click ID, and then it sends a post back URL to your affiliate network or ad tracking software.
5. Finally, your affiliate network matches the received click ID to the original click event and credits you for a successful conversion.

When it comes to choosing an S2S tracking tool, consider using reliable software like RedTrack. It’s a feature-rich tool that simplifies S2S and postback tracking at any scale. Best of all, neither cookie restrictions nor ad blockers can limit your ability to track ads, even when working with multiple traffic sources.

Why Does Postback Tracking Matter for Affiliate Marketing?

Overall, it is a very accurate affiliate ad tracking method, and you get a lot more information about the user’s actions. It is also among the extremely secure and reliable affiliate conversion tracking strategies (whereas Pixels can sometimes misfire).

Postback URLs use direct server communication to record conversion events, enhancing data accuracy and quality. This means you won’t have to deal with lost commissions since you’re properly credited each time a user takes a desired action.

What else makes it important for affiliates? For starters, it attributes each conversion event to the right affiliate, campaign, and traffic source in real time, helping understand exactly which campaigns drive results, even across complex cross-device tracking of customer journeys. Moreover, it delivers granular, real-time conversion data you can act on immediately, cutting underperforming traffic and doubling down on what’s working.

What Are the Pros and Cons of the S2S Postback Method?

There’s more to the story. Let’s dive into other meaningful benefits and downsides worth taking note of.

Pros of Server-to-Server Postback Tracking

The S2S approach is a privacy-first approach using first-party data collection that is rapidly gaining popularity among marketers, and here’s why:

• Accurate tracking — gives you full visibility into each user’s journey. With ad tracking software like RedTrack, every click carries session data, making it easier to see which campaigns are delivering the most results and create unified customer profiles.
• Can bypass browser restrictions — it doesn’t rely on cookies or client-side scripts, which means it bypasses browser restrictions and keeps your data intact.
• Flexible triggers — you can trigger postbacks at any event stage, for instance, count a conversion after a product is shipped or a customer completes a phone call, which gives you more control over when a conversion is officially registered.
• Reliability and privacy — as major browsers keep restricting third-party cookies and privacy regulations tighten, postback tracking is a reliable data collection method where everything happens on the server side. It gets past ad blockers and privacy settings but remains privacy-focused, so no sensitive data is passed to third parties, making sure you stay compliant with relevant regulations.
• Helps prevent fraud — server to server tracking postback comes with built-in tools to block fake conversions and suspicious traffic, protecting your budget and campaign integrity. It helps you spot suspicious patterns like unusually high conversion rates, rapid-fire submissions, or conversions from flagged IP addresses. As such, this helps affiliates and advertisers flag shady patterns only to get paid for legit actions.
• Reliable reporting — because everything happens server-to-server, you avoid the inconsistencies of client-side tracking, even if a user disables their cookies, your conversions still get tracked, ensuring reliable reporting and attribution.

Cons of S2S Postback Tracking

As advantageous as it is, opting for the postback URL approach with server-to-server tracking has its drawbacks:

• More complex setup — S2S integration typically involves some level of technical expertise to properly pass click IDs, set up conversion URLs, and make sure both your affiliate network and ad tracker are aligned.
• Resource-intensiveness — S2S tracking can put an extra load on your server infrastructure, particularly if you’re dealing with high traffic volumes or running multiple campaigns at the same time; you also need good hosting and uptime in order not to lose conversions.
• Higher cost — some ad tracking platforms that allow advanced postback URLs can be expensive, yet pricing plans usually depend on the number of events you track, your traffic volume, real-time analytics, and fraud detection. If you’re not tech-savvy, you may also need to pay for a developer to set everything up.

Comparing Tracking Pixel vs Postback URL Tracking

What can you track with a tracking pixel and S2S postback? Whether you’re using simple pixel tracking or a more advanced postback S2S, both methods can capture many types of customer data:

• Clicks — record every time a user taps your link, so you’ll know exactly where the click happened.
• Conversions — capture the moment a user completes a desired action and attribute it to the right campaign.
• Conversion statuses — track the status of each conversion in real time, whether it’s pending, approved, declined, or flagged for review.
• Transactions — monitor transaction details like order value, currency, and transaction ID (great for e-commerce campaigns and sales funnels).
• Events — beyond purchases, track other conversion events like button clicks, ebook downloads, newsletter signups, and how much time someone spends on a page.

But how do you decide between tracking pixels and postback tracking? The table below highlights how they differ.

	Tracking Pixel	Postback URL Tracking
How it works	Uses a pixel embedded in the user’s browser	Sends data server-to-server directly after a conversion event
How it’s collected	Relies on browser cookies and client-side scripts	Handles conversion data server-side
Data accuracy	Data can be lost if a user disables cookies or interrupts page loading	Highly accurate because tracking is independent of user actions
Complexity	Easy to set up by pasting a tracking pixel in your web page’s HTML	Requires technical expertise to implement and maintain server-side integrations
Reliability	Can be restricted by ad blockers and privacy settings	Not affected by browser settings and ad blockers
Cost implications	Usually free or low-cost to implement	Costs are higher due to server integration
Security	Vulnerable to data leaks, privacy issues, and malicious attacks	Reduces exposure to fraud and data leaks by handling information securely on the server
Use cases	Basic ad campaigns, email marketing	Mobile app installs and in-app events, performance-critical ad campaigns, lead generation

As you see, tracking pixels are easy and inexpensive to set up, so it might make sense to use them for basic ad campaigns and sometimes they’re applicable for email marketing. Yet, because they depend on browser cookies and can be blocked by ad blockers, there could be a risk of getting an incomplete picture of your data or even its loss.

On the other hand, the S2S postback URL approach operates server-to-server, which is why the collected data is much more accurate, secure, and reliable. The implementation costs may be higher, though, and the setup process is quite intricate. Despite that, it’s a value-delivering method that can be invaluable for performance-critical campaigns and lead generation.

Final Thoughts on Tracking Pixel vs S2S Postback URL Tracking

The best-fit tracking method depends on your budget, technical expertise, and the kind of campaign you’re running. If your network doesn’t support S2S, you dabble mostly in organic traffic, and you are not very tech-savvy, the pixel could be enough for you. However, for more secure and accurate tracking and attribution, the postback URL method is a top choice that helps you stay compliant and bypasses browser limitations.

At RedTrack, we recommend S2S postback tracking as the smarter, superior method to capture user behavior. As such, the tool has 200+ integrations and makes it easy to connect your campaigns with major ad platforms like Facebook, Google, Bing, and more. In just a few steps, you can set up postback integrations that automatically send conversion data straight to your traffic sources. This saves you hours of manual work and syncs all your data in real time.

Want to learn more about how server-to-server postback tracking works? Sign up for a demo to see for yourself.