Broad vs Narrow Meta Ad Audiences for Healthcare — The Per-Specialty Verdict

Why "broad always" and "narrow always" are both wrong

The fixed-philosophy camps each have an argument:

• Broad camp: Meta's algorithm is smart enough to find the right audience within a broad pool. Trust the algorithm.
• Narrow camp: Healthcare patients are specific. Targeting must reflect that specificity. Don't waste impressions on irrelevant audiences.

Both are right sometimes and wrong other times. The right framing isn't "what's my philosophy" — it's "what's the verdict for my account this week."

Per-specialty audience baselines

Across the ICG portfolio, the typical optimal audience size by specialty:

• IVF — 2-10M narrow (specific intent + age-banded). Above 15M, CPL rises sharply because of low-intent dilution.
• Dental implants — 2-8M narrow. Patient persona is fairly specific (age 35-65, income tier-1).
• Orthopaedic joint replacement — 5-15M narrow. Age 50+ targeting with specific income + location bands.
• Aesthetic + cosmetic derm — 10-25M broader. Demand is wider; Meta's algorithm efficiency higher with broader pool.
• Hair transplant — 8-18M moderate. Mix of broad demand + specific intent signals.
• Cardiac surgery — 5-15M narrow with specific city + age slicing. Very high-trust consideration.
• Paediatric — 5-15M moderate. Mother-persona targeting + geographic specificity.
• Mental health / psychiatry — 10-25M broader. Stigma-aware targeting; broader serves anonymity-preferring patients.

Why the answer shifts week-to-week

Three factors shift the broad vs narrow optimal:

1. Audience saturation

Run a 5M narrow audience for 8-12 weeks; you'll exhaust the optimal pool. CPL rises. Same week, expanding to 15M broader audience can reduce CPL because the algorithm finds adjacent intent signals in the wider pool.

2. Competitive intensity

When a competitor enters your specialty + city with aggressive Meta spend, your narrow audience CPM rises faster than the broader audience CPM (because competitors target the same narrow pool). Shifting broader during a competitor escalation can preserve CPL.

3. Seasonality

Aesthetic specialties around festival + wedding season: broader audience works because everyone is in-market. Off-season: narrower works because only intent-driven patients are searching.

The weekly verdict methodology

Meta Catalyst IQ's Audience Size verdict each Monday checks 5 inputs:

1. CPL by audience size bucket (≤2M, 2-10M, 10-20M, 20M+) over last 7 days
2. Hold Rate by audience size bucket
3. Result Rate by audience size bucket
4. CPM trend by bucket (rising → saturation signal)
5. Frequency by bucket (high frequency → saturation imminent)

The output: which audience size delivered best CPL × engagement quality this week, and the reallocation recommendation for next week (typically 10-25% budget shift).