Meta's algorithm learns from events: who submitted a lead, who bought, who reached checkout. If events get lost to ad blockers, cookie banners or site errors, ads optimise on incomplete data — and cost per lead climbs. That is why event setup is the first step of any Meta Ads engagement we run, before any budget goes live.
In short: use the pixel and the Conversions API together, send the same event_id for deduplication, pass hashed contact data with user consent and optimise campaigns for the event closest to revenue.
Why you need two sources
| Pixel (browser) | Conversions API (server) | |
|---|---|---|
| Where it fires | In the visitor's browser | On your server or CRM |
| Ad blockers | Can block it | No effect |
| Offline events | No | Yes: payment, lead qualification, calls |
| Complexity | Low | Requires integration |
Together they give the fullest picture: the pixel captures on-site behaviour, the server confirms events that happen later or outside the browser.
Which events to send
- Lead — form or request submitted.
- CompleteRegistration — sign-up in the product.
- InitiateCheckout and Purchase — for online sales, with value and currency.
- Qualified lead — a custom event from your CRM once a manager confirms the lead is a fit.
Step-by-step setup
- Write an event plan. Which actions matter to the business and where they happen.
- Install the pixel via a tag manager or directly, respecting cookie consent.
- Connect the Conversions API — from your server, CRM or a partner integration.
- Set up deduplication. The same event from browser and server must share an event_id or it is counted twice.
- Send matching parameters. Hashed email and phone, IP, user agent, click IDs — only with consent and within your privacy policy.
- Verify in Events Manager. Test events, match quality score, duplicate warnings.
Common mistakes
- The Lead event fires when the form opens, not when it is submitted.
- No deduplication — conversions double and reports lie.
- Purchase without value — you cannot optimise for value.
- Campaigns optimise for clicks even though events exist.
Frequently asked questions
Does a small business need the Conversions API?
Yes, if you spend more than a few hundred dollars a month. Losing even 10–20% of events noticeably hurts learning.
How do I send CRM sales data to Meta?
Via the Conversions API: when a deal changes status in the CRM, the server sends an event with customer identifiers. This is set up under API integrations.
How do I respect cookie consent?
The pixel and personal data sharing must follow the user's choice and your privacy policy. More on compliant measurement in our marketing analytics service.
Want Meta ads to learn from accurate data? Send a request on the Meta Ads page and we will audit events, set up the pixel and Conversions API, and only then launch the budget.