How can I “upgrade” my subscription?

Some sites GMB works with provide subscription options for customers (for example, to different areas of paid content). If you do not currently have access to all of these paid areas, you can choose to “upgrade” to gain access.
This is administered by GMBill’s Client (that is, not by us directly), so you’ll need to log in on their site to upgrade. They probably have a FAQ on this as well!