Some clients structure their products in to different accounts. Leads like to have an overview of the whole account. They could be added manually each time a new product launches. But it is also handy for this to be automated by having an ALL ACCOUNTS/ADVERTISERS option when choosing the data source
This is a must have. In supermetrics, when no account is selected it defaults to all accounts (behind the scenes) so that the account list is dynamic.
Our account list changes often and it would be painful to have to go back and update every report to add new accounts.