62% of bookings invisible to Meta after iOS 14 — CAPI recovered 58%

The situation

A medspa chain with 4 locations in Florida was using Meta Ads as their primary acquisition channel. They used an online booking platform (Acuity Scheduling). Post-iOS 14, their Meta reported bookings dropped 60% while their actual Acuity bookings stayed flat. The gap was real and growing.

The problem

The Meta pixel was placed on a thank-you page after booking. iOS users who denied ATT tracking completed bookings but generated no pixel event. There was no Meta CAPI implementation. 62% of actual bookings — mostly from iOS users — were invisible to Meta's algorithm. Meta was optimizing on the 38% of Android and ATT-opt-in users, generating audiences that skewed away from the actual customer profile.

What we did

1. Connected to Acuity Scheduling's webhook system — triggered on every confirmed appointment
2. Built a serverless function (Cloudflare Worker) to receive Acuity webhooks and forward to Meta Conversions API as Schedule events
3. Passed hashed customer email and phone from Acuity booking data to improve match rate
4. Implemented event_id deduplication using Acuity appointment ID — prevents any residual pixel events from double-counting

Why it worked

Local service businesses that use third-party booking platforms (Acuity, Calendly, Mindbody, etc.) face a specific CAPI challenge: the confirmation page is on the booking platform's domain, not yours. You can't install a pixel there. The only solution is a server-to-server webhook from the booking platform's event system to Meta CAPI — bypassing the browser entirely.