Paul Krugman emails, apropos of Alan Furst:
I discovered Alan Furst at the Trenton train station, three or four years ago. And I think there's a lesson in that.
Background: Trenton station is a miserable, grimy little place that happens to be my gateway to the world, because many Amtrak trains stop there but not at Princeton Junction. The newsstand is tiny, selling at most 50 different books at any given time. But whoever decides on the book selection has eccentric, pretty good taste. And so there, circa 2002, was Dark Star, which wasn't even a new book.
The thing is that I would never have looked for Furst on my own - in fact, I wasn't even into spy thrillers at that point. And I would never ever have found him on Amazon, which only confirms your tastes, without broadening them.
Two lessons: randomize now and then, look for serendipity. And when in Trenton, do check out the train station newsstand. You'll probably be pleasantly surprised.
There's probably a connection here to sociologist Mark Granovetter's work on the strength of weak ties: Granovetter believes that you're unlikely to find out about a possible job from someone you know well--because, by and large, you know what they know and they know what you know. You're more likely to find out something useful from somebody who you know only casually, because the overlap in your respective domains of knowledge is relatively small.