Your Google Ads account is hitting its conversion targets. Cost per conversion looks healthy. Smart Bidding is in the learning phase and everything appears stable.
But revenue is flat. Leads are not closing. The business is not growing in proportion to the ad spend.
This is one of the most common and most damaging configurations in Google Ads: vanity events set as primary conversions. Scroll depth, time on site, video views, and button clicks that do not represent genuine business outcomes - treated as the primary signal for Smart Bidding to optimize toward.
The algorithm does exactly what it is told. It finds users who will scroll 75% of a page. It finds users who will watch a video. It bids higher for those users. And it ignores whether any of them ever buy anything.
What Primary vs. Secondary Conversions Actually Mean
Google Ads conversion actions fall into two categories that have entirely different effects on how your campaigns behave.
Primary Conversions
Primary conversions are used by Smart Bidding to optimize bids. When you set a conversion action as primary, you are telling the algorithm: this is the outcome I want more of, and I want you to find users who will do this.
Smart Bidding observes which clicks lead to primary conversions and learns to favor similar users, queries, times, and devices. The entire bidding strategy - Target CPA, Target ROAS, Maximize Conversions - is calibrated against primary conversions.
Secondary Conversions
Secondary conversions are recorded for observation only. They appear in your reports and give you visibility into lower-funnel engagement, but they do not influence bidding decisions.
The distinction is critical. A conversion action set as secondary might as well not exist from the algorithm’s perspective. A conversion action set as primary is the north star that your entire campaign is optimized toward.
What Counts as a Vanity Event
A vanity event is any user action that:
- Occurs frequently and easily
- Looks like engagement on paper
- Does not directly represent a business outcome (revenue, lead, sign-up, call)
Common vanity events that get mistakenly set as primary conversions:
| Event | Why It Looks Useful | Why It Is Not a Business Outcome |
|---|---|---|
| 75% scroll depth | Measures content engagement | Does not mean the user is interested in buying |
| Time on site (>2 min) | Suggests the user is engaged | Engaged visitors do not necessarily convert |
| Video view (50% or 75%) | Shows content consumption | Watching a video does not indicate purchase intent |
| PDF download | Suggests interest in content | Informational download, not a commercial action |
| Social share click | Shows advocacy | Does not indicate a personal intent to purchase |
| Outbound link click | Shows general activity | Context-dependent, often not commercial |
| Page view (specific page) | Tracks visits to key pages | Visiting a pricing page ≠ requesting a quote |
| ”Add to cart” in low-intent accounts | Tracks funnel progress | Without purchase tracking, optimizes for intent, not action |
Some of these events are genuinely useful as secondary conversions - they provide insight into behavior. The problem is exclusively when they are primary conversions driving Smart Bidding.
How It Happens: The Three Common Entry Points
Vanity events end up as primary conversions through three predictable routes.
1. Auto-Suggested Conversions
Google Ads now proactively suggests conversion actions based on your linked GA4 property or website behavior. These suggestions appear as notifications in the account and can be added with a single click.
The suggestions are not filtered by business relevance. Google’s algorithm identifies events that fire frequently and suggests them as conversions. Scroll depth events from GA4, session engagement events, and video interaction events all get recommended.
If someone clicks “Add suggested conversions” without reviewing each action individually, the account gets populated with vanity primary conversions automatically.
2. Mass GA4 Event Imports
When a GA4 property is linked to Google Ads and the account manager marks GA4 events as conversions, they can all import as primary by default.
A GA4 setup that tracks scroll depth, time thresholds, button clicks, video plays, and engagement events - properly configured for analytics purposes - is not a Google Ads conversion setup. Those events are useful in GA4 for understanding behavior. They are harmful in Google Ads as primary conversions.
The problem is that mass-importing GA4 events requires no individual judgment about which events represent business outcomes. The import is one action. The damage is across every event.
3. Account Setup Without Conversion Strategy
New accounts or accounts rebuilt without a clear conversion tracking plan often add conversion actions based on what is available rather than what matters. The conversion linker is firing. Some events are being tracked. The goal count looks good.
Without understanding the primary/secondary distinction, every tracked event defaults to primary. The account ends up with eight primary conversions - page views, scroll depth, a button click, a video view, a form visit, and the actual lead form submission - all weighted equally in Smart Bidding.
The algorithm cannot distinguish between a scroll and a sale. It optimizes for the average.
What Smart Bidding Does With Vanity Conversions
Understanding the mechanism makes the damage concrete.
Smart Bidding Optimizes for Volume and Pattern
Smart Bidding’s objective is to generate as many conversions as possible at or below your target CPA, or to maximize conversion value relative to spend. It does this by learning which signals predict conversion.
If scroll depth is a primary conversion, Smart Bidding learns:
- Users on mobile devices scroll more often → bid higher for mobile
- Users who arrived from certain queries scroll more often → bid higher for those queries
- Users from certain demographics scroll more → adjust audience bids
Every one of these optimizations may be completely irrelevant to who actually buys from you.
The Optimization Diverges From Business Reality
Users who scroll 75% of a blog post are not the same as users who purchase. In many accounts, they are negatively correlated - information-seeking users who are not yet in a buying mindset spend time reading content, while high-intent buyers go directly to the pricing or contact page.
An account optimized toward scroll depth will actively compete harder for users who are not ready to buy, while bidding less aggressively for commercial queries from users showing real purchase intent.
The account performs “well” by its own metrics. CPA against scroll depth stays on target. But the business metrics diverge.
The Learning Loop Compounds the Problem
Once Smart Bidding has been trained on vanity conversions for several weeks, the learning is embedded in the model. The patterns it has learned reflect vanity engagement, not commercial behavior.
Even after you fix the conversion setup, the algorithm needs time to re-learn. The bad data does not just disappear - it has to be diluted by new, correct conversion signals. Depending on how long the account ran on vanity conversions, recovery can take weeks.
Diagnosing the Problem in Your Account
Step 1: Audit Every Primary Conversion Action
In Google Ads, go to Goals → Conversions → Summary. Look at every conversion action. For each one, ask:
If a user does this, does money change hands or does a genuine sales relationship begin?
Actions that qualify as primary conversions:
- Purchase / transaction
- Lead form submission (with contact information provided)
- Phone call (minimum duration, not just any call)
- Appointment booking
- Free trial sign-up (if sales qualified)
- Account creation (if it represents genuine product engagement)
Actions that should be secondary or removed:
- Scroll depth
- Time on site
- Video views
- Page views
- PDF / resource downloads
- Outbound clicks
- Button clicks that do not trigger a lead or transaction
Step 2: Check the “Primary” Column
In the conversion summary, each action has a “Primary” or “Secondary” designation. If you see scroll depth, time on site, or video events listed as Primary, those need to change.
Step 3: Look at the Conversion Action Category
Google assigns categories to conversion actions (Purchase, Submit lead form, Book appointment, etc.). Filter your list by category. Anything categorized as “Other” or “Page view” should be scrutinized immediately.
Step 4: Compare Conversion Volume to Business Outcomes
Pull your total conversions for the past 30 days from Google Ads. Compare it to:
- Actual form submissions in your CRM
- Actual purchases in your e-commerce platform
- Actual phone calls with meaningful duration
If your Google Ads reports 1,200 conversions and your CRM shows 80 leads, you have 1,120 conversions that are not leads. They are vanity events masquerading as outcomes.
The ratio tells you how contaminated your primary conversion setup is.
How to Fix It Without Disrupting Your Campaigns
Switching conversion actions in a live account needs care. Smart Bidding learns from the current conversion setup, and sudden changes can trigger re-learning periods and performance volatility.
Step 1: Create the Correct Conversion Actions First
Before changing anything, make sure you have conversion actions tracking genuine business outcomes:
- Purchase with transaction value (if e-commerce)
- Lead form submission (if lead gen)
- Phone call with a minimum duration (60-90 seconds filters out wrong numbers)
- Any other genuinely commercial action
Test these in GTM Preview mode and verify they fire correctly. Check that data is flowing into Google Ads.
Step 2: Change Vanity Events to Secondary
In Google Ads, open each vanity conversion action and change the Optimization setting from Primary to Secondary. Do not delete them yet - they have historical data and may be useful for analysis.
Changing to secondary removes them from Smart Bidding’s optimization input immediately. They continue to record in your reports.
Step 3: Set New Business Conversions as Primary
Mark your genuine conversion actions (purchases, leads, calls) as Primary. If these have been collecting data as secondary, they already have history and Smart Bidding will begin using them.
If the new conversion actions are brand new with no history, expect a learning period of 1-4 weeks while the algorithm accumulates enough data to optimize reliably. You may see increased performance variability during this time - this is expected and healthy. The algorithm is learning what actually matters.
Step 4: Adjust Targets to Reflect Reality
Your previous CPA target was calibrated against vanity conversions that fire easily and often. Genuine business conversions are rarer.
A campaign with a target CPA of €5 based on scroll depth might need a target CPA of €80 based on lead form submissions. These are not the same metric and the targets are not comparable.
Recalibrate your target CPA and target ROAS against the true economic value of your conversion actions. Base it on your actual customer lifetime value or revenue per lead, not on what the account was previously hitting.
The Special Case of “Add to Cart” Without Purchase
E-commerce accounts frequently fall into a specific version of this trap: tracking “add to cart” as a primary conversion without tracking purchases.
Add to cart is a meaningful funnel event. It indicates intent. But the gap between add to cart and purchase is significant in most industries - cart abandonment rates of 70-80% are typical.
An account optimized for add-to-cart finds users who add things to carts. It does not find users who complete purchases. The two populations overlap but are not the same. Users who abandon carts habitually, users who add items speculatively without planning to buy, and users who are comparison shopping all generate add-to-cart events without revenue.
Smart Bidding optimizing for add-to-cart will find more of all of these users - not more buyers.
The fix: Track purchase as the primary conversion. Use add-to-cart as a secondary conversion to monitor funnel health. If purchase data is sparse, consider smart bidding strategies that account for lower conversion volume (tROAS with a floor, or Maximize Conversions with a CPA bid limit) rather than using a higher-volume vanity proxy.
When Lower-Funnel Data Is Genuinely Unavailable
Some advertisers use vanity conversions as a crutch because they genuinely do not have enough lower-funnel conversion data. A lead generation account with 10 form submissions per month cannot train Smart Bidding effectively on that volume alone.
This is a real constraint, but vanity events are not the solution.
Better options when lower-funnel volume is too low:
Use broader but still meaningful conversions. If purchases are sparse, use purchases + high-intent form submissions together as primary. If lead form submissions are sparse, include qualified phone calls. Broaden the definition of a meaningful conversion rather than diluting it with meaningless ones.
Import offline conversion data. If you qualify leads in a CRM, import CRM-qualified leads back into Google Ads as offline conversions. This gives Smart Bidding a more accurate signal even from limited volume.
Lower the portfolio target temporarily. Set a less aggressive CPA target while the account builds conversion history. Do not substitute bad conversion data to compensate for low volume.
Consider value-based bidding with micro-conversions. If you assign values to different conversion actions (a form submission = €5 value proxy, a phone call = €20 value proxy, a purchase = actual revenue), Smart Bidding can optimize for the blended value - without making scroll depth part of the equation.
The instinct to add more conversions to increase volume is understandable. But adding the wrong conversions to hit volume thresholds is worse than having fewer, accurate conversions. An account with 15 correct conversions per month will outperform an account with 500 vanity conversions per month over any meaningful time period.
Key Takeaway
Smart Bidding is only as good as the conversion actions it is trained on. It does not understand business outcomes - it learns patterns. If you teach it that scroll depth is success, it becomes very good at finding users who will scroll 75% of your page. Those users are not your customers.
The conversion setup in a Google Ads account is a direct statement to the algorithm about what you value. Vanity events in the primary position are a statement that says engagement metrics matter more than business outcomes. The algorithm will act accordingly.
Audit your primary conversion actions. Remove anything that does not represent genuine commercial intent. Fix the conversion actions to track what actually moves the business. Accept the recalibration period.
The discomfort of a learning phase and temporarily higher reported CPAs is far preferable to months of an algorithm that is quietly optimizing toward the wrong people.
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