I went to the website dedicated to my game in order to make a purchase (or manage my account somehow), and I noticed G1 Credits.
In order to better serve the players of our games, we have created GamersFirst. Once you create a GamersFirst account, you can make purchases and manage your accounts for ALL GAMES USING ONE ACCOUNT! And, what’s more, we have created a currency, G1 Credits, with which you can make all purchases. We just thought it would make things much more convenient. That said, if you already have an account and you want to make purchases the old way, you currently can still do that.