Each Marketo instance (full or sandbox) are entirely separate, so unless there is a special partner tool, you cannot view all 4 at the same time.
What do you mean by "usage"?
I take it you mean actual instances with 1-1 relation with an SFDC org, NOT workspaces?
A
Anonymous
June 23, 2013
Josh, I already know that they are entirely separate. So, how do I manage them. I'm suppose to have 4 Marketo instances but I've only been notified on how to use a single instance.