Santiago says that the only connection she has to the author is that she started following them on social media after reading their first book. As far as she's concerned, that's the only relationship that she has with the question (although we only have that evidence to go on). The easy conclusion to reach, then, is that Amazon is somehow data-mining everybody's Facebook and Twitter accounts to better understand its customers. Although how it's able to do that to such an extent that it's capable of swooping down on a single relationship, we'll never know. It's also unclear if eBook authors and reviewers are being monitored more closely than anyone else.
Unfortunately for us, the naturally-secretive company isn't likely to divulge how it made that connection any time soon. That hasn't stopped us from emailing in the hope of getting some sort of response, but we're 99 percent sure that all of our questions will be met with a firm "no comment."
Update: We've received a response from Amazon that states:
"We have a long standing policy of not commenting on individual customer accounts or on specific methods of determining review manipulation. However, when we detect that elements of a reviewer's Amazon account match elements of an author's Amazon account, we conclude that there is too much risk of review bias that would erode customer trust, and thus we remove the review. I can assure you that we investigate each case.We have built mechanisms, both manual and automated over the years that detect, remove or prevent reviews which violate guidelines. We encourage authors to continue to build their network and community as they normally would. This will not impact customer reviews."