Symantec, since you do not offer your Anti-Virus product on CD/DVDs any longer, I can only surmise that you do not have any idea how bad internet access is out here in the boondocks. Making your excellent product available on disk, even at extra cost to the user, would be a great help to those who are not located in the cities across America.
Symantec and other manufacturers no longer offer a CD as by the time you get it, it will be way out of date.
Best to buy online or from a reputable retailer such as Amazon, and activate the product with the key which they will send you.
In any case Symantec offer the option to burn a Bootable Recovery Tool which is useful to get out of trouble if hit by malware.
http://security.symantec.com/nbrt/nbrt.aspx