About: EU and NA servers [Product Keys]

Okay, I know that both version are global and stuff, but what I'm asking is when I subscribe an account for the US version of City of Heroes, does it only affect the US client of the game or does it also affect both EU and US client versions?

I'm trying to help my girlfriend subscribe her account to CoH by buying a US version of the product key, but she lives in Europe, and I don't know if I have to buy the EU version of City of Heroes instead of the US version, which would probably affect which client she downloads.

EDIT: If only if I could change the [Product Keys] to [Client version]. It would make more sense...

If you're creating a new account, buy whichever you want, it doesn't matter. If you're upgrading/reactivating an existing account, it has to match the region of the box she used to originally create the account.

EDIT: With regards to the client version: I don't think it matters which client you have any more. If it does, there are workarounds to force it to download the right client. Sorry, but I can't remember exactly what they are.

NA codes and EU codes are not interchangeable, unfortunately.