What is Conversion?
Also known as: Conversion event, Goal completion, Desired action
What is a conversion?
A conversion is any user action that an advertiser counts as a success. The exact action depends on the business goal.
For an e-commerce store, a conversion is usually a purchase. For a SaaS tool, it's a free-trial signup. For a lead-gen site, it's a form submission. For a mobile game, it's an install or a first-session purchase.
Every paid ad platform organizes itself around conversions:
- The bidding algorithm optimizes toward them.
- The attribution system assigns credit to the ads that drove them.
- The reporting dashboard ranks campaigns by them.
Define the conversion sloppily and every number downstream is wrong.
Types of conversions
Conversions split into two layers. Macro and micro.
Macro conversions
The primary business outcome. One per funnel.
- E-commerce. Purchase.
- SaaS. Paid subscription or free-trial signup.
- Lead-gen. Qualified form submission.
- Mobile apps. Install plus first key event (level 5, first deposit, first ride).
- Finance and crypto. First deposit or KYC completion.
Bidding strategies optimize against the macro event. ROAS, CPA, and LTV calculations all roll up to it.
Micro conversions
Smaller steps toward the macro goal. Useful as optimization signals when the macro event is too rare.
- Email or newsletter signup
- AddToCart or InitiateCheckout
- Pricing page view
- Video watched to 75 percent
- Account created (pre-purchase)
A campaign with 3 purchases per week can't train a bidder. The same campaign with 300 AddToCart events per week can. Most performance teams use micro events as a fallback optimization target until macro volume scales.
Standard events vs custom events
Every ad platform ships a fixed list of named events. Per Meta's standard events documentation, the core nine are Purchase, Lead, CompleteRegistration, AddToCart, InitiateCheckout, AddPaymentInfo, Subscribe, ViewContent, and Search. Google Ads conversion actions cover similar ground with categories like Purchase, Lead, Sign-up, and Page view. GA4 events work the same way, with recommended events plus custom events for anything outside the list.
Use standard events whenever possible. They get pre-built reports, better optimization, and cleaner attribution.
How conversion tracking works
Conversions are recorded through two channels working in parallel.
Browser-side: the pixel
A pixel is a snippet of JavaScript installed on the confirmation page. When the page loads, the pixel fires an event to the ad platform. The payload includes the event name, a value, a currency, and any custom parameters.
Browser pixels are easy to install and increasingly unreliable. iOS App Tracking Transparency, Safari ITP, and ad blockers strip 15 to 40 percent of events from typical accounts.
Server-side: the Conversions API
The fix is server-to-server tracking. Your backend sends the conversion event directly to the ad platform via an authenticated API call. Meta calls this Conversions API. Google calls it Enhanced Conversions. TikTok calls it Events API.
Server-side events bypass the browser. Ad blockers can't strip them. Cookie restrictions don't apply.
The standard setup runs both. The pixel fires in the browser. The server fires the same event with a matching event_id. The platform deduplicates and counts the conversion once.
Why conversion definitions matter
The definition of a conversion shapes three things at once.
Bidding. Smart Bidding strategies (tCPA, tROAS, Maximize Conversions) only work when the conversion event is clean and frequent. Define it too broadly (every PageView) and the algorithm chases low-value users. Define it too narrowly (only purchases over $500) and the algorithm starves for data.
Attribution. The attribution window decides which ad gets credit. Meta defaults to 7-day click plus 1-day view. Google Ads defaults to data-driven attribution within 30 days. Same conversion, different credit, different reported ROAS.
Reporting. Conversions roll up into cost per acquisition, ROAS, and LTV. If finance and marketing measure conversions differently, every meeting becomes a debate about whose number is right.
A clean conversion definition is upstream of every performance metric.
Real-world example: defining a conversion for a launch
A skincare brand launches its first paid funnel on Meta and Google.
The team defines two conversion events:
| Event | Type | Value | Source |
|---|---|---|---|
Purchase | Macro | order total | Pixel + CAPI |
AddToCart | Micro | product price | Pixel + CAPI |
Spend in month one runs $14,000. The pixel records 412 purchases at an average order value of $68. Reported revenue: $28,016. Reported ROAS: 2.0.
Server-side CAPI catches an additional 71 purchases the browser missed. After deduplication, real conversion count: 483. Real revenue: $32,844. Real ROAS: 2.34.
The team also pulls AddToCart data. Of 6,200 AddToCart events, 7.8 percent converted. They build a 7-day retargeting audience for the rest. Spend $1,500. Recover 89 additional purchases at a CPA of $16.85.
The campaign math only works because the conversion event was defined cleanly, fired from both browser and server, and tracked through the full funnel.
Conversions in an AI ad platform
In a connected ad-creation-and-launch platform like Coinis, conversion setup is wired in by default.
When you connect a Meta or Google ad account, the platform reads existing conversion events, attribution windows, and standard event mappings. Generated creatives auto-tag with UTM parameters that match each conversion goal. Server-side events fire alongside pixel events, deduplicated by event_id without manual config.
Reporting rolls every campaign up to the conversion event the brand actually cares about: a paid order, a qualified lead, an installed app. The marketer sees ROAS, CPA, and conversion volume in one view. The engineering work of pixel install, CAPI plumbing, and event mapping disappears.
Define the conversion once. Every campaign measures itself against it.
Related terms
Frequently asked questions
What counts as a conversion?
Anything the advertiser defines as success. The default is a purchase, but signups, leads, installs, demo bookings, and email subscriptions all count. Each ad platform supports standard events (Purchase, Lead, SignUp, AddToCart) plus custom events for anything outside the default list.
What is the difference between a macro and a micro conversion?
A macro conversion is the primary business goal: a purchase, a signed contract, a paid subscription. A micro conversion is a smaller step toward it: an email signup, a pricing-page view, a video watched to 75 percent. Most accounts optimize on macro events and use micro events as backup signals.
How does an ad platform know a conversion happened?
Two signals. A browser-side pixel fires on the confirmation page and sends an event to the platform. A server-side event fires from your backend through APIs like Meta Conversions API or Google Enhanced Conversions. Modern accounts run both and deduplicate by event ID.
Why does my ad platform report different conversions than Google Analytics?
Different attribution models. Meta uses a 7-day click, 1-day view default. Google Ads uses data-driven attribution. GA4 uses last non-direct click. Same purchase, three different counts. Pick one source of truth for reporting and reconcile the others to it.
Can a single user trigger multiple conversions?
Yes. Most platforms count every conversion event by default. If a user buys twice in one week, both Purchase events count. For lead campaigns, deduplicate by email or user ID at the backend before sending the event, otherwise CPA looks artificially low and the bidder over-spends.