I said environmentally sound because that USB drive is likely to be useless as well. I doubt Chris is going to be buying 32GB drives, nor likely 16GB. That leaves the possibility of buying the smallest drives available which will probably be smaller than what someone might already have. They'll either let it sit somewhere, give it away or toss it.

Besides, it's easier to store a DVD, or multiple of them, in a folder of some sort, rather than having a USB drive kicking around possibly getting mistaken for any other drive, getting misplaced, lost or erased.

Savvy customers will make a backup, or Chris can provide two copies right away.