*And now for the fine print...
The USPS "Click and Ship" system prints out a combined label and postage, and, due to the size of the label, it's meant for large envelopes and packages. -The "C&S" labels may be too big to use on CD mailers. However...
The USPS also has an online "Shipping Assistant" which prints out labels only. However, the "Shipping Assistant" also allows online processing of domestic and international mail, Priority Mail, and Customs Forms. So, if you already have a postage meter at home, this is the other alternative, AND you can even integrate it with your postage meter to print out mailing and confirmation barcodes.