Meta and Google’s bidding algorithms are extremely good at optimizing toward whatever event you tell them is success. When that event is 'form fill,' they faithfully deliver more form fills — many from low-intent users. When the event is 'demo attended' or 'MQL,' the algorithm changes who it shows the ad to, and the cost-per-lead goes up but cost-per-customer goes down.
Volume thresholds
Meta and Google both need at least 50 conversions per week per ad set to optimize reliably on an event. If your Demo Booked volume is below that threshold, optimize on the closest mid-funnel event you do have volume for (usually MQL) and use Demo Booked as a secondary signal for retargeting and lookalikes.
If you’re below 50/week even on MQL, stay optimized on Lead but make sure Cometly is pushing every downstream event back to the platforms via Conversion API. The platforms can use the deeper events to enrich audience quality even when they can’t formally optimize against them.
- Above 50 weekly Demo Booked → optimize on Demo Booked or Demo Attended
- 20–50 weekly MQL → optimize on MQL, use Demo Booked as secondary
- Below 20 weekly MQL → optimize on Lead, push deeper events for audience enrichment
Expected patterns
When you switch the optimization event from Lead to MQL or Demo Booked, expect cost-per-lead to roughly double and lead volume to drop 30–60%. That’s the algorithm finding higher-intent users instead of low-intent ones.
The number that should improve is cost-per-customer or cost-per-pipeline-dollar. If you don’t see that improvement within 4–6 weeks, the issue is usually creative-audience fit, not the optimization event.
What to watch for.
- Switching the event without enough volume
Below 50 conversions/week the algorithm can’t learn. Stay on the higher-volume event until you cross the threshold.
- Panicking when CPL goes up
CPL going up is the goal, not a problem. The number that matters is cost-per-customer.
- Forgetting to enrich the event payload
Send hashed email, phone, IP, click ID with every CAPI event. Without identifiers, match quality crashes and the optimization signal weakens.
Recap.
- Push at least one mid-funnel event (Demo Booked or MQL) to every paid channel
- Wait until the event has at least 50 weekly conversions before optimizing on it
- For lower-volume B2B, optimize on MQL and use Demo Attended as the secondary objective
- Watch CPL go up and SQL volume go up — that’s the algorithm finding higher-intent users
- Match-quality scores improve dramatically because Cometly sends richer first-party data