Snarl: while your theory is fairly accurate, you made a fairly large mistake on the number of CD manufacturers. True, there are much fewer then the number of brands out there, but much more then 4
To name a few:
Taiyo Yuden; Mitsui; Mitsubishi Chemicals; Prodisc; Princo; Ritek; Digital Storage Technology; Daxon Technology; Finex Disc Technology; Kodak Japan; Imag Optical Storage; Lead Data; Mediastar Technology; Moser Baer India Ltd; Nan Ya Plastics Corporation; and Sky Media Manufacturing.
Believe me, that's a SMALL list