Bonus for bringing new players?

[Demisis_P2P]

One week of free gold time isn't much.
If players get one month free they might actually try to start playing GK or Zone and get some stuff on those servers.
After they've been playing there for one month the chances of them upgrading their own account again so that they can keep playing there and keep their stuff will increase dramatically.
It'll also help to keep those servers hustling-and-bustling. At the moment GK is pretty dead, if 20 players start playing there on their free month then even more people are going to start playing there (it's a pretty acknowledged fact that servers with the most players attract more players, while servers with almost no players generally stay that way).