When we first announced the capability to dial out directly from your mobile phone, you had to be a ring group member for this to work.
At the time it didn't occur to us that some colleagues might want to use this feature to call customers without having to be part of group receiving inbound calls.
So we've added the ability to invite people into your team in the same way that you add participants into ring groups.
The difference to ring group membership is that you don't need to deal with inbound calls. You can now use SwitchSmith for outbound calling independently from inbound call handling.