How Google Ads Tracks Conversions?
Check out the videos below at the end
Yes, Google Ads primarily tracks conversions using cookies (first-party and third-party) and other tracking mechanisms like Google Click Identifier (GCLID). Here’s how:
Click-Based Tracking (GCLID)
When someone clicks on a Google ad, a unique tracking parameter (GCLID) is added to the URL.
Example: www.yoursite.com/?gclid=123abc456xyz
When they land on your site, Google Analytics or Google Tag Manager stores this ID in a cookie.
If the user converts within the set window (e.g., 30 days), Google attributes the conversion to the original ad.
View-Through & Engagement Tracking (Cookies & Device Fingerprinting)
If a user sees a display ad (without clicking) and later visits your site organically, Google checks browser cookies and tracking data to see if that user was exposed to the ad.
If the user engages (like watches 10+ seconds of a video ad), Google tracks that interaction through YouTube’s tracking systems and matches it with later conversions.
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We will refer the below Screenshot to explain
Action Optimization
Primary vs. Secondary Action
Primary action used for bidding optimization (Selected in the screenshot)
This means Google will actively optimize your bids to get more of these conversions.
Example: If "Purchase" is set as the primary action, Google's smart bidding (e.g., Target ROAS, Max Conversions) will try to get more purchases.
Secondary action not used for bidding optimization
This means Google will track the conversion, but it won’t optimize bids to get more of them.
Example: If you track "Add to Cart" as a secondary action, you can see the data, but Google won’t bid based on it.
Warning: "Purchase" is Not Meaning: If you don’t explicitly add the "Purchase" goal to your campaign settings, Google won’t count these conversions in your reports or optimize for them.
Fix: Go to Goals > Account Default Goals and include "Purchase" if you want every campaign to recognize it.an Account Default Goal
Google is telling you that the "Purchase" conversion action is not included in your account-level default goals.
If you want Google’s AI to prioritize purchases, you must:
Set "Purchase" as a primary conversion
Make sure it's included in account default goals (if needed)
If you're running awareness campaigns and just want to observe how many people complete an action, use Secondary Action instead.
If your goal is sales, make sure "Purchase" is primary and included in your campaigns. Otherwise, Google will ignore it for bidding.
Value
This setting is about assigning a monetary value to each conversion so that Google Ads can measure Return on Ad Spend (ROAS) and optimize bids accordingly.
Option 1
Use the same value for each conversion
Every conversion is assigned a fixed value, no matter the purchase amount.
Example: If you’re tracking lead form submissions, you might assign ₹500 per lead, assuming that’s the average revenue per lead.
Best for: Businesses with fixed-value conversions, like service businesses or single-price products.
Option 1 : To track every conversion takes place (more than 1 product / qty purchased)
Option 2 : To track only 1. Sign ups (Netflix Subscription)
1. View-Through Conversion Window
What it is: This tracks when a user sees your ad but doesn’t click on it. Instead, they later go to your website and convert.
When to use it: If you're running display ads, YouTube ads, or awareness campaigns, where clicks aren’t always expected but brand recall is strong.
Example: You run a Display ad for a Digital Marketing Course. A user sees it but doesn’t click. Three days later, they Google your brand, visit your website, and buy the product. Google Ads will credit that conversion under the view-through conversion window.
2. Engagement-Through Conversion Window
What it is: This is used mainly for YouTube ads and display ads where the user engages (e.g., watches 10+ seconds of a video ad) but doesn’t click, and later converts.
When to use it: If you're running video ads that are designed for engagement rather than immediate clicks.
Example: A user watches 15 seconds of your YouTube ad for a coaching program but doesn’t click. Two days later, they search for your business, sign up for a free webinar, and later buy. That conversion is counted under engagement-through conversions.
3. Click-Through Conversion Window
What it is: This tracks conversions from users who clicked your ad and then converted within a set period (default is 30 days).
When to use it: If you’re running search ads, performance max, or direct-response ads where immediate action is expected.
Example: A user searches for "best CRM software for small businesses", clicks your Google Search ad, but doesn’t buy right away. A week later, they revisit the site and subscribe to your CRM plan. Google attributes the conversion to the original click.
Why Different Time Limits?
View-Through Conversions (30 days)
These are set shorter (default 30 days) because seeing an ad doesn’t create a strong long-term influence.
If a person doesn’t act within a month, Google assumes the ad didn’t contribute much to the decision.
That's why we kept default value 1. Also that depends on the purchase type or the ad copy and some other factors. But usually the engagement should come as quickly as possible.
Click-Through Conversions (Default 30 days, Max 90 days)
Since a click is a stronger intent signal, the window can be longer.
Example: If you're selling expensive software or real estate, people might take weeks or months to decide.
That’s why Google allows up to 90 days for high-consideration products.
Quick Question - does this mean that we should plan campaign and keep it running for that long? And this is why we need tracking for ongoing campaigns before we set up campaigns?
Engagement-Based (Varies)
YouTube ads often default to a 3-day window for engagement-based conversions because watching an ad isn't as strong as a click but stronger than a view.
But if your business has a longer sales cycle, you can extend it.
If you’re selling low-ticket items (e.g., Rs.600 Shoe), most buyers will convert quickly → shorter conversion windows (7-14 days) make sense.
If you’re selling high-ticket coaching programs or B2B software, buyers take longer to decide → use a 60-90 day click-through window to capture delayed conversions.
Set your conversion windows based on your actual sales cycle. Otherwise, you might be cutting off valuable conversions and under-reporting ad performance.
