Google and Meta are very good at finding more of whatever you tell them counts as a conversion. For most lead businesses, that's a form fill or a call. So that's what they find: people who fill out forms and make calls. Whether those people ever buy is invisible to the platform.
The problem with form fills as the goal
A platform bidding on leads will find the cheapest leads it can. Cheap leads skew toward low intent, poor fit, and people who never answer the phone. Your cost per lead falls. Your cost per customer climbs. The algorithm is doing exactly what it was asked to do.
What offline conversions do
Offline conversions send outcomes from your CRM back to the ad platform: this lead became a qualified opportunity, this one became a customer worth this much. The platform matches each outcome to the click that started it, then bids toward people who look like your buyers instead of your form fillers.
Both major platforms support it. Google matches outcomes using the click ID captured with each lead. Meta uses its Conversions API with hashed contact details.
What you need
- A way to capture the click ID or contact details with every lead
- A CRM that records what happened next: qualified, sold, and for how much
- A regular upload, daily if possible, from the CRM to each platform
- Enough volume to learn from. If sales are rare, send an earlier step, like a qualified appointment, alongside them.
What changes
Lead volume often dips at first. That's expected: the platform stops buying the cheap leads that never closed. Over the following weeks, close rates usually rise and cost per customer falls. Judge it on cost per customer, not cost per lead.
Where to start
Check whether your CRM records the outcome of every lead and the source it came from. If it does, the hard part is done. If it doesn't, that's the first fix, and it pays off well beyond ad bidding.