Why Did I Buy This Thing?

I just bought the  ASUS External Slim DVD-RW, Model: SDRW-08D1S-U

I bought this unit because I now had three micro PCs or laptops in the house without optical drives.  Unless pre-installed, kinda hard to get an OS on them without one of these.  I bought it from my friendly neighborhood Best Buy.  They had a couple different makes/models.  The ASUS price' was about midrange ($65) and I've never had a problem with anything else from ASUS, so...

The package contained the optical drive, a stand, driver disk, instructions, and USB cable.  The only way to power the device is via the double-ended USB; I would have thought there was an external power option or adapter included, but no.