A couple commenters point out that this isn't really a social graph, which is totally fair objection to the way the author is talking about this stuff. But my m

A couple commenters point out that this isn't really a social graph, which is totally fair objection to the way the author is talking about this stuff. But my main concern is that this doesn't present any evidence that Amazon is doing this (and I'm not saying they aren't), but just suggests why it might be in Amazon's best interest to do so. They put together a couple graphs, one of which appears to be based on publicly visible "customers who bought X bought Y" data, but that data has been around and visible, and scrape-able for years, and they don't present any reasons for believing that this data is being used by Amazon in a different way now than it was 5 years ago. So, in other words, reckless speculation.