Hacker News Reader

Amazon already has been doing this as well.

They started to recommend some items related with books I have never bought online, just after I got them at local bookstore by credit card.

View on HN

Isn't there a difference? Google is sharing that offline purchase insight with advertising clients, rather than simply using that data itself, as does Amazon.

Where the advertising client is the local bookstore that he purchased the book from.

Reply on news.ycombinator.com