One of the pull quotes in the article states that Amazon reminds the customer if they've purchased the same book twice. Oddly enough, about an hour prior to reading the article, I repurchased a book deliberately. I'd given one as a gift, and I wanted to read it myself. There was about a 4 day interval between the two purchases.

I wondered if Amazon would alert me about it, because that's how I'd design the system. They didn't.

Does that have any implications for the article's accuracy?