Free during beta, but how much will it cost after? Are you going to limit access through the Referrer header? Why do I need a Heroku addon if I can just use a F

Free during beta, but how much will it cost after? Are you going to limit access through the Referrer header? Why do I need a Heroku addon if I can just use a Firesize URL from anywhere automatically? How much does it cost to run a massive service like that?