Imperium has a great public relations company working to keep him in the spotlight and make sure everyone knows what a great hero he is.  It helps that he really is sincere and a great guy. 

All this marketing is paid for by product endorsements for various companies.  He won't endorse a product he won't use, and he tries to research each company before endorsing it.  Typically part of his compensation is also in the form of goods and services.  This helps him "earn" a living as Imperium so he can still have a secret identity.

(In terms of temperment, Imperium borrows a lot from Batman.)