Sub-ID tracking explained: how to pass custom parameters to optimize affiliate campaigns

If you're running affiliate campaigns across multiple traffic sources like PropellerAds, Taboola, or solo ads, you already know that tracking clicks and conversions is only half the battle. The real question is: which specific ad, keyword, or placement actually drove that conversion? That's where sub id tracking affiliate comes in. Sub-IDs (also called sub-IDs, tokens, or custom parameters) let you pass additional data through your tracking link — like source, campaign ID, creative ID, keyword, or device type — so you can slice your conversion data by those dimensions. Without sub-IDs, you're flying blind on what's actually working. This article explains how to implement sub-ID tracking, what each sub1–sub5 parameter typically holds, and how to configure it in Adtraxo for per-campaign analytics with geo and device breakdowns.

What exactly is sub-ID tracking in affiliate marketing?

Sub-ID tracking is the practice of appending custom parameters (like &sub1=, &sub2=) to your affiliate tracking URL so that when a user clicks, the tracker captures that additional data alongside the click. When that user later converts, the tracker passes those parameters back to your affiliate network or CRM via a postback URL. This allows you to answer questions like:

• Which ad creative generated the most sales?
• Which keyword in my native ads campaign had the highest ROI?
• Which solo ad seller delivered the best EPC?
• Which placement ID on PropellerAds drove the most conversions?

Most affiliate trackers, including Adtraxo, support up to 5 custom sub-IDs (sub1 through sub5). These are essentially dynamic tokens you can map to any variable your traffic source passes. For example, when you send a click from a Taboola campaign, you can pass the campaign ID, the creative ID, and the site ID in sub1, sub2, and sub3 respectively. When the conversion fires, you see exactly which combination of those variables converted.

How to set up sub-ID tracking in your affiliate tracker

Setting up sub-ID tracking is a three-step process: configure your tracking link, pass the parameters from your traffic source, and then map them in your conversion postback. Here's how it works in practice with Adtraxo.

Step 1: Build your tracking link with sub-ID placeholders

In Adtraxo, when you create a campaign, you'll see fields for sub1 through sub5. You can name them anything — "source," "keyword," "creative," "placement," "device" — and then set them to pull from dynamic tokens. For example, if you're using PropellerAds, you might set sub1 to {campaign_id}, sub2 to {creative_id}, and sub3 to {zone_id}. Adtraxo automatically generates a tracking link that looks like this:

https://your-custom-domain.com/click?campaign_id=123&sub1={campaign_id}&sub2={creative_id}&sub3={zone_id}

Step 2: Pass the parameters from your traffic source

Most traffic sources support dynamic tokens in the destination URL. In PropellerAds, you'd paste your tracking link into the "Destination URL" field and append the tokens. In Taboola, you'd use %c for campaign ID, %a for ad ID, and %s for site ID. In solo ads, you'd manually append the seller's campaign ID or email list name. The key is that your tracker receives these values in the URL query string.

Step 3: Map sub-IDs in your postback URL

When a conversion happens, Adtraxo sends a postback to your affiliate network with the sub-ID values. You configure the postback URL to include tokens like {sub1}, {sub2}, etc. For example, if your network expects a parameter called &click_id= and you want to pass sub1, your postback would look like:

https://network.com/conversion?click_id={sub1}

Adtraxo automatically replaces {sub1} with the actual value captured at click time. This is the core of sub id tracking affiliate — you're passing the custom data through the entire funnel.

What should you put in sub1, sub2, sub3, sub4, and sub5?

There's no universal standard, but here's a common mapping that works across most traffic sources:

• sub1: Traffic source or campaign ID (e.g., "propellerads_camp_456")
• sub2: Creative or ad ID (e.g., "banner_v2_blue")
• sub3: Keyword or search term (for native or push ads, use the keyword group)
• sub4: Placement or site ID (e.g., "site_xyz.com")
• sub5: Device type or OS (e.g., "iOS_15" or "Windows_10")

You can also repurpose these for A/B testing. For example, if you're running a split test on two landing pages, you could pass the landing page variant as sub5. Then in Adtraxo's analytics, you can filter conversions by sub5 to see which variant performed better.

How to analyze sub-ID data in Adtraxo for better campaign decisions

Once you have sub-ID data flowing, the real value is in the analysis. Adtraxo's per-campaign analytics let you break down clicks, conversions, and ROI by any sub-ID parameter. Here's how to use it:

1. Go to the campaign report — click on any campaign in your dashboard.
2. Select "Sub-ID breakdown" — you'll see a table showing each unique sub-ID value and its performance metrics (clicks, conversions, revenue, ROI, EPC).
3. Sort by ROI or EPC — instantly identify which sub-ID value is your top performer. For example, you might find that sub2="banner_red" has a 300% ROI while sub2="banner_blue" has only 50% ROI. Pause the blue banner and scale the red one.
4. Apply geo and device filters — combine sub-ID analysis with geo and device breakdowns. You might discover that sub2="banner_red" only works on iOS in the US, but fails on Android in Brazil.

This level of granularity is what separates profitable campaigns from break-even ones. Without sub-ID tracking, you'd be optimizing based on aggregate data, missing the micro-level insights that drive real ROI improvements.

Common mistakes when implementing sub-ID tracking (and how to avoid them)

Even experienced affiliates make these errors. Here's what to watch out for:

• Mismatched parameter names: Your traffic source might call a parameter {campaign_id} but your tracker expects {sub1}. Always test with a dummy click first. Use Adtraxo's click test feature to see exactly what values are captured.
• Forgetting to append tokens in the postback: If your postback URL doesn't include the sub-ID tokens, the conversion data will be missing those parameters. Always double-check your postback configuration.
• Using too many sub-IDs without a naming convention: If you mix up what sub1 and sub2 represent across campaigns, your reports become confusing. Document your mapping per traffic source. For example, always use sub1 for campaign ID and sub2 for creative ID on PropellerAds.
• Not encoding special characters: If your sub-ID value contains spaces or special characters (like "banner v2 (blue)"), URL-encode it before passing. Most modern trackers handle this automatically, but it's worth verifying.

Why sub-ID tracking is essential for fraud detection

Fraud detection tools, including Adtraxo's built-in fraud module, rely heavily on sub-ID data. When you see a sudden spike in conversions from a specific sub-ID value (like sub4="site_badactor.com"), you can quickly identify fraudulent activity. Adtraxo's fraud detection checks for IP velocity, datacenter IPs, bot user agents, uniqueness conflicts, and invalid referers — all of which can be cross-referenced against sub-ID data. For example, if sub1="campaign_123" shows 100 conversions from 50 different IPs in 5 minutes, that's a red flag. The fraud detection will flag it, and you can pause that sub-ID immediately.

Frequently asked questions

Sub-ID tracking isn't optional if you're serious about affiliate marketing. It's the difference between guessing and knowing. By passing custom parameters like source, keyword, creative, and placement, you can optimize at the micro level — pausing losers and scaling winners with surgical precision. Adtraxo makes this straightforward with its sub1–sub5 configuration, per-campaign analytics with geo/device breakdowns, and built-in fraud detection that cross-references sub-ID data. Start with the free plan (10 links, 5k clicks/month) and upgrade to Pro ($49/month) for unlimited everything. Sign up at Adtraxo.com and start tracking your sub-IDs today.