How to Set Up Tracking for Ad Campaigns: S2S Postback, SubID, and Pixels Explained

Key Takeaways

S2S postback is a server-side tracking method independent of browsers, cookies, and AdBlock
Click ID links each click to a conversion, subID ties the conversion to a specific zone
Without subID you see conversions but don't know where they came from — zone optimization is impossible
Pixel tracking is easier to set up but loses 20–30% of conversions
AdsCompass supports S2S integrations with Keitaro, Binom, RedTrack, Voluum, and BeMob

Why Tracking Is Needed and Why You Can't Optimize Without It
Tracking answers one question: where did the conversion come from. Without the answer to that question, everything else — working with zones, managing bids, scaling — loses its purpose. Picture this: you launched a push campaign on AdsCompass and got 20 conversions in 48 hours. The campaign is profitable. But which zones did those conversions come from? If only 15 out of 200 zones are converting, the other 185 are draining budget. Without a tracker, you won't see this because the ad network's statistics show clicks and impressions by zone, but not conversions. The conversion happens on the advertiser's side — on the landing page, in the app, on the offer's website. To link that conversion to a specific click in a specific zone, you need a bridge between two systems. That bridge is a tracker and S2S postback. Per IAB standards, server-side tracking has become a baseline requirement for performance campaigns, especially after tightened privacy policies in iOS and Chrome
How Does S2S Postback Differ from Pixel Tracking?
The two methods solve the same task — passing conversion data back to the ad network — but work in fundamentally different ways. A pixel is a JavaScript snippet installed on the "thank you" or confirmation page. When a user lands on that page, the code fires and sends conversion data. The problem: if the user closes the page before it loads, uses AdBlock, or the browser blocks third-party cookies, the pixel doesn't fire and the conversion is lost. Industry data suggests pixel tracking loses 20–30% of conversions. After Apple introduced ATT and Safari ITP restrictions, losses on iOS traffic are even higher.
S2S postback works differently. Conversion data is transmitted directly between servers — the advertiser's server (or tracker) sends an HTTP request to the ad network's server. The user's browser is not involved. AdBlock has no effect. Cookies aren't needed. The conversion is recorded even if the user closed the tab immediately after the action.
When to use a pixel: simple funnels without a tracker, quick tests, situations where server integration isn't possible. When to use S2S: always, when you have a tracker and server access. For performance campaigns in ad networks, S2S is the standard.
How S2S Postback Works: Step-by-Step Mechanics
The entire S2S tracking process is built on one principle: a unique click identifier travels through the entire chain from ad network to conversion and back. If the identifier is lost at any stage, the conversion can't be attributed. That's why it's important to understand each link: click ID, postback URL, and subID. These three elements work together to ensure a complete data cycle: from ad click to conversion record in the tracker, tied to the specific source. Below is how each one works.
Click ID: The Foundation of the Entire Chain
Click ID is a unique identifier generated with each ad click. The ad network creates a click ID and passes it in the URL when the user transitions to the landing page. The tracker saves this ID and ties all subsequent user actions to it. When a conversion occurs, the click ID is sent back to the ad network via postback — and the network understands exactly which click led to the result. Without click ID, attribution is impossible.
Postback URL: How the Conversion Returns to the Tracker
A postback URL is the server address to which the tracker (or advertiser's server) sends conversion data. The URL contains the click ID and, optionally, additional parameters: conversion value, event type, status. The ad network receives this request and records the conversion in its statistics. On AdsCompass, the postback URL is generated in the advertiser dashboard and contains preset parameters — it needs to be copied into the tracker's settings.
SubID: Why It's Essential for Zone Optimization
SubID is a parameter that passes additional information about the click: zone ID, GEO, device, OS. This is what makes tracking not just "functional" but useful for optimization. Without subID, you see: "the campaign got 20 conversions." With subID, you see: "zone 12345 delivered 8 conversions, zone 67890 delivered 0 conversions with 500 clicks." It's precisely subID that enables building white- and black-lists by zone — the key optimization method in ad networks. On AdsCompass, available tokens for subID include zone_id, geo, device, os, and other parameters passed in the campaign URL.
How to Set Up Tracking: Step-by-Step Instructions
Setting up S2S postback looks complex at first glance, but in practice it comes down to four steps, each taking 5–15 minutes. The core principle: the tracker and ad network need to "agree" on the data transfer format — which parameters are passed, under which names, and where the postback is sent. Most errors occur precisely at the parameter mapping stage — when the token name in the network doesn't match the name in the tracker. Below is the step-by-step process.
Step 1: Choose a Tracker
AdsCompass supports S2S integrations with Voluum, Keitaro, Binom, RedTrack, BeMob, and PeerClick. Ready-made postback URL templates are available in the dashboard for each one. If you use a different tracker, Custom integration with manual parameter setup is available.
Step 2: Create a Campaign in the Tracker and Get the Postback URL
In the tracker, create a traffic source (AdsCompass), configure tokens (click_id, zone_id, geo, device), and obtain the postback URL. This URL contains a placeholder for click ID — when a conversion fires, the tracker substitutes the real ID and sends the request.
Step 3: Set Up the Postback in the Ad Network
In the AdsCompass dashboard, go to the Tracker section, select your tracker from the list (or Custom), and paste the postback URL from step 2. Make sure the macros/tokens map correctly: click_id in the network = click_id in the tracker.
Step 4: Test the Setup
Make a test click through the campaign, verify in the tracker that the click ID was recorded. Then generate a test conversion (via the tracker's test tool or manually through the postback URL with a test click ID). The conversion should appear in both systems — the tracker and AdsCompass — tied to the correct click ID. If it doesn't, check the macro mapping. Don't launch paid traffic until the test setup works.
What Mistakes Break Tracking and How to Avoid Them
Tracking breaks silently — you won't get an error on screen. You'll simply stop seeing conversions, and it will seem like the campaign isn't working, even though the problem is in the setup, not the traffic.
The first and most common mistake: mismatched macro names. Click ID in the ad network might be called click_id, cid, or clickid — while the tracker expects a different format. One wrong character and the entire chain breaks. Always check documentation on both sides before setup.
The second: not passing subID. The postback works, conversions come through — but without zone_id, you don't know which source they're from. Zone optimization becomes impossible, and you lose tracking's main advantage.
The third: not testing before launch. Launching a paid campaign with an unverified postback is a guaranteed loss of data for the first 24–48 hours. That data is unrecoverable.
The fourth: forgetting about cost. A tracker is an additional expense: $50–200 per month for mainstream solutions (Voluum, RedTrack, Binom). For budgets under $500/month, this is a noticeable line item. But without a tracker, you'll lose more on unoptimized campaigns.
How Tracking Works on AdsCompass
AdsCompass provides everything needed for S2S tracking setup within the self-serve platform. Ready-made integrations with Keitaro, Binom, RedTrack, Voluum, BeMob, and PeerClick — with preset postback URL templates and automatic token mapping. Custom integration is available for other trackers.
Available tokens for passing in the campaign URL: click_id, zone_id, geo, device, os, browser, carrier. This enables detailed analytics in the tracker: seeing conversions broken down by zone, GEO, device, and operating system. White- and black-lists are built on the basis of this data — the key optimization tool referenced across all our campaign launch guides.
The platform operates on CPC (pop, push, in-page) and CPM (native, banners, pre-roll, TMA) models, covers 200+ GEOs, and processes over 900 million impressions daily. All AdsCompass formats support S2S tracking, and the built-in anti-fraud system additionally filters invalid traffic — so the data in your tracker reflects real users, not bots.
FAQ
Can I launch a campaign without a tracker?
Technically, yes. AdsCompass shows clicks, impressions, and spend in the dashboard. But without a tracker, you don't see conversions by zone, can't build white/black-lists, and can't calculate ROI. For an initial test at $20–30, this is acceptable. For regular operation, it's not.
How much does a tracker cost?
Depends on the solution. Binom — from 69/month (self-hosted). RedTrack — from 75/month. Voluum — from 199/month. Keitaro — from 49/month (self-hosted). BeMob — has a free tier with limitations. For a beginning buyer with a budget under 500/month, BeMob or Keitaro is the optimal starting point.
What is click ID and why does it get lost?
Click ID is a unique click identifier generated by the ad network. It gets lost in three cases: a redirect on the landing page strips URL parameters, the landing page doesn't pass click ID further down the funnel, or the parameter name in the URL doesn't match what the tracker expects. Check the URL after every redirect.
How does subID differ from click ID?
Click ID identifies a specific click — one click = one unique ID. SubID passes additional information about the click: zone, GEO, device. Click ID is needed for conversion attribution. SubID is needed for analytics: understanding exactly where the conversion came from and optimizing by source.
How do I verify that the postback is working?
Make a test click through the campaign, check in the tracker that the click ID was recorded. Then generate a test conversion (via the tracker's test tool or manually through the postback URL with a test click ID). The conversion should appear in both systems — the tracker and AdsCompass.
Which tracker is best for a beginner?
BeMob — free tier, cloud-based, no server required. Keitaro — affordable but self-hosted (needs a VPS). For starting out with a budget under 500/month, both work well. Voluum and RedTrack are for teams with large volumes and advanced analytics needs.
About the Author
Vlada, Business Developer at AdsCompass. Works with advertisers and publishers in digital advertising, specializing in performance formats and international markets. Helps partners build traffic acquisition and monetization strategies across 200+ GEOs.