Board Thread:Game Discussions/@comment-24.90.68.68-20140105190338/@comment-217.19.30.150-20140414093735

AFAIK BlueStacks will use the same device ID for each new install, just like bouncing your account between 2 devices and referring from the device where your main account isn't located multiple times, which got people banned...

And it doesn't look like Gree is putting another referral special in play, so referrals aren't worth much other than a few gems.