[ma2rten]

As much as I share your admiration for O'Reilly, this is seems to be common practice. It's just more expensive to get the items back in inventory again than what they are actually worth.

See this thread: "Microsoft suggests customer donate extra X-Box they sent him." http://news.ycombinator.com/item?id=3434404

[babarock]

Vaguely related, my mother in law wakes up one day and finds over 20 box of various cookies delivered to her apartment. She contacted the company to let them know of the mistake. They answered that it would cost too much to get them back in inventory.

I've been eating cookies for the past month now; what a happy mistake :)

[dholowiski]

This is extremely common, but it's all about how you handle it. When I was working for a company that shipped large products, I once told a customer to keep one and they were angry. We literally had to pay for someone to pick it up and take it to a electronics recycling depot.