I think this comes down to microsofts distribution media and their licenses being two different things.

We used to buy license packs for software (say 300 licenses for MS Office), and they'd only send us a couple of disks, which suits us just fine as we copy them up on to the server and download from there. We would just be throwing out 200 odd disks if they sent us one per license. If we ever needed more, Microsoft would just send us more disks without questioning it. This sounds like something similar. Someone has bought a couple of hundred version of XP for a company, and they've demanded all the disks. But the company has registered XP using the licenses they were issued (I'm guessing there aren't seperate license numbers inside the disk packs like there are with the retail versions). So in other words, handy if you snap your existing XP disk, but apart from that worthless..... unless you want to be Roger the cabin boy.