things that make you go, "hmmm..."

Okay - I like to think of myself as an educated, literate, more-or-less well-read, informed citizen... but still...

How did Amazon tag me for the following recommendation:

Save 34% at Amazon.com on "Teach Yourself Estonian Complete Course (Book + 2CDs) (Ty: Complete Courses)" by Mare Kitsnik

???
I don't get that many recommendations from Amazon, and most of them are more-or-less on-target. "Teach Yourself Estonian"??? No clue.

Completely pointless trivia from high school:
The gang I hung out with in high school were... well, sort of nerdy (sorry, TedTheCat!): chess club, bridge/chess/Risk on Friday nights.
Many of us participated in the Tulsa Public Library's "Book Discussion Club."
At one corner of the stacks in the main library was prominently displayed a book on Serbo-Croatian. I'm not sure that any of us ever in fact took this book off the shelf, but the title was prominent as we wended our way to the room in which the "Book Discussion Club" was meeting. It became something of a joke. "Russell Sype": Serbo-Croation for "piglike in appearance." [substitute names as required for the occasion.]

Is Amazon reading my psychic past?

Sing a song!