The Credit/Billing Department
These departments do exactly what you'd think. The credit department helps new advertisers establish credit, and once they do, the billing department bills the advertisers.

We'll get into more detail later about the things you'll need to do to get an account credit, but remember, the credit department can take away credit as well and block the computers from accepting a reservation for an ad if the advertiser hasn't been paying his bills. We'll talk about what it takes for someone to be put on credit hold, and what it takes to remove the hold, in the section on New Accounts. Check this out before you get a message that one of your advertisers can't run this week due to bad credit.