Do I pay for your ‘credits’ plus text messaging fees from my carrier in the US, or do I just pay your credits?

For the ZygoHubs service. you’ll pay one credit for each message that gets delivered by us to each member of your group (so, four messages if your group has five people in it) and you’ll pay your carrier for sending one message to the Zygo group number. We advise our US customers to try the service out using their free credits first, as we haven’t tested the service with every US CDMA carrier.