A lead campaign only learns what you tell it: send each lead’s outcome from your sales calls back to Meta through the Conversions API, keyed on the lead ID, and Meta can start looking for people like your real buyers instead of people who like filling forms.
A lead generation campaign has one job as far as Meta is concerned: get the form filled. It has no idea what happens next. It never hears that the lead picked up, that the number was fake, or that the person bought a flat three weeks later.
Your sales team knows all of that. They find it out on the first call. And in most agencies that knowledge goes into a spreadsheet or a CRM and stops there, while the campaign keeps learning from the one signal it has: who submits forms.
That is how a campaign ends up cheap and useless. It is doing exactly what it was told.
What Meta will take back
Meta has a version of its Conversions API built for exactly this, meant for CRMs. For each lead you send an event: the lead’s ID and the stage it reached. The stage names are yours. “Qualified”, “Site visit”, “Sale”, “Junk”: whatever your team actually uses.
The lead ID is the 15 to 17 digit number every Instant Form submission already carries. That is the whole match. You do not need to send the person’s name, phone number or email, because Meta already knows which submission the ID belongs to.
Three rules from Meta’s own documentation matter in practice:
- Send every stage as it happens, including the first one, the lead arriving. Meta uses the whole path, not just the good ending.
- An event can be at most seven days old when it reaches Meta. A lead marked good last month and sent today is too late.
- Upload at least once a day. A weekly export misses the seven-day window for most of the week.
The part nobody likes: someone has to mark the leads
None of this works without a person deciding, for each lead, whether it was any good. That is the whole input. Automation can carry the mark to Meta; it cannot make it.
In our experience this is where it breaks, not in the API. The team is busy, the marks happen in someone’s head, and the campaign never hears. The fix is boring: make marking a lead take one click in the place where the team already sees the lead, and make it part of the call rather than a job for Friday.
The API is the easy half. The hard half is getting a salesperson to spend one second saying which leads were real.
When to switch the campaign to Conversion leads
Sending outcomes helps even if you change nothing else: your reporting starts to show which campaigns bring real buyers. The bigger step is Meta’s Conversion leads performance goal, where the campaign optimises for the stage you choose instead of for form fills.
Meta sets a bar for it. The account should be generating around 200 leads a month from Instant Forms, and the stage you optimise for should be reached by between 1% and 40% of those leads within 28 days. Below that there is too little signal for the campaign to learn from, and above 40% the stage is too common to separate good from ordinary.
Expect Conversion leads to cost more per lead. That is the point: it is buying fewer, better leads. So do not judge it on cost per lead. Judge it on cost per good lead, from the same marks you are sending, and test it against the current setup rather than switching a working campaign over on faith.