How to monetize product comparison website?

Hey everyone!

First post here!

I recently came with the idea of creating a directory for medical services in my area. I recently had the need for such a service but noticed that this doesn't exist at where I live. However, the idea is still in its infancy and I still have a lot of validations to do.

One of the biggest challenges I have is what is the best way to monetize such a service? Some obvious answers I have are:

1 - Take a cut from bookings

This would require integrations with medical providers and thus I would need enough traffic to begin working with providers, (as I need to prove my worth first). Thus this would be further down the road.

2 - Advertising from medical service providers

The problem I see here is unless the app/website gets a tremendous amount of traffic, otherwise the income would be very modest. It might be better to keep the app/website ad-free to make it look less spammy and provide a better visitor experience.

Are there other methods that I can monetize this? Does anybody run a directory service here and would care to share your experience?

Thank you!