Don't host in such a way that you're paying for traffic... Hetzner, OVH and Packet all have dedicated servers where you don't pay for the traffic, inbound or outbound.
Edit: judging by other comments here, it might seem like US zone of Fly.io is in fact hosted in Packet so they are probably themselves not paying for the traffic. Maybe they are using Hetzner for the EU zone (or OVH for that matter).
Packet charges for outbound bandwidth. The places you can get close to free on outbound bandwidth don’t give you the ability to do anycast and tend to over subscribe their networks.
We’d like to grt network prices down but we can’t run our service on ovh or Hetzner.
Don't host in such a way that you're paying for traffic... Hetzner, OVH and Packet all have dedicated servers where you don't pay for the traffic, inbound or outbound.
Edit: judging by other comments here, it might seem like US zone of Fly.io is in fact hosted in Packet so they are probably themselves not paying for the traffic. Maybe they are using Hetzner for the EU zone (or OVH for that matter).