Hello samnoble18 ,
That is a wonderful Question.
If i understand you correctly. You are an advertising agency that is going to be managing mulitple accounts?
Currently we do not have the feature to have one master login for mulitple account (of different advertisers). We do have the function of having mulitple logins for accounts but every login will be able to see sensitive information (Billing, Addresses, CC information).
However, to manage multiple account you would have to sign up each advertiser with unique logins and passwords.
If you need help signing up please contact support.
Thank you
adCenter Support Rep