There are 2 main areas to familiarize yourself with, to manage multiple marketplaces or accounts within you main PPC Storm account; 1. Marketplace Switcher, and 2. All Marketplaces Dashboard.
To use the marketplace switcher to seamlessly move between to a different marketplace, or another account that is connected - click the marketplace name in the top right of the screen (to the left of your user name).
Next, select the account you'd like to switch to.
You can use the search bar to find the account quicker if needed!
BOOM! You're in the new marketplace!
The other area is the 'All marketplaces dashboard' that is explained in the DASHBOARDS page. This will help you keep a birds-eye overview of all marketplaces connected to your account from one screen.