I occasionally look at a liberal-leaning website called Talking Points Memo. It displays ads in the right column of their web page.  One of them is for Barnes & Noble, and it features four books I might be interested in buying from http://www.bn.com.  Today, three of them were thrillers or mysteries by authors II’d never heard of.  The fourth was The Portal, an alternative history novel by Richard Bowker.  Hey, that’s me!

So, how is B&N figuring out what books to display in the ad?  They could be looking at my sales history, but that would tell them I have already bought The Portal from them. (I know that sounds pitiful, but I wanted to goose the novel’s sales rank when it first came out; I promise I won’t do it again.)  Surely that should factor into their algorithm.  Are they tracking which pages I visit on their web site?  But I have never gone anywhere near the other authors whose books they want me to buy.  Is my publisher paying B&N to improve the book’s ad placement generally?  If so, they didn’t bother to tell me.

I find it very mysterious.