Start with compliance credentials. Any agency handling healthcare marketing must understand PHIPA (Personal Health Information Protection Act) in Ontario or equivalent provincial laws, plus sector-specific advertising restrictions from regulatory colleges. Ask directly how they handle patient data in analytics, retargeting, and CRM integration. An agency that doesn't immediately address privacy isn't worth your time. Review their healthcare portfolio with skepticism. Generic "we work with clinics" claims mean nothing. You want agencies that have worked in your specific vertical—dentistry, physiotherapy, mental health, cosmetic surgery, or family medicine all have different patient journeys and compliance considerations. Ask for anonymized performance data: patient acquisition cost, conversion rates from organic search, and how they attribute offline appointments to online campaigns. Evaluate their technical SEO and content approach. Healthcare sites need schema markup for medical businesses, proper local SEO for multi-location practices, and content that satisfies Google's E-E-A-T standards without making unverified medical claims. The agency should know the difference between informational content that ranks and service pages that convert appointments. At Ottawa SEO, we see healthcare clients need both—blog posts that answer patient questions and location pages optimized for "dentist near me" searches. Test their reporting transparency. Healthcare marketing often involves long sales cycles and offline conversions. The agency should track form fills, phone calls, and ideally integrate with your practice management software to close the loop on which channels drive actual patients. Monthly reports should show rankings, traffic, and leads by service line, not just vanity metrics. Watch for red flags: agencies promising specific rankings within weeks, using stock medical photos everywhere, or suggesting keyword stuffing. Healthcare SEO is methodical, not quick. Expect 4–6 months before seeing meaningful organic growth, and choose an agency that sets realistic timelines based on your local competition and domain authority.