As part of the Game Testing program we're doing various events. One event, designed to test Guild functionality, offered an incentive for getting involved - the possibility of an extra invite granted as a 'plus one'. This is a one-off event.
The number of invites issued through this incentive will be small, and those who receive the ability to invite others will be randomly selected. In comparison to the total number of people in Game Testing, it will be a tiny fraction.
There is no general 'invite a friend' program as part of Game Testing, and nothing is currently planned along those lines. Invites are continuing to be sent randomly to those who have opted in to test.
As a reminder, anyone who is part of the Game Testing program is bound by the terms of the Game Testing Agreement. As such, you are allowed to tell the world that you are in testing, and that's all.
We'll be closing this thread to stop further speculation and will close further threads on the same topic without notice.