[matsemann]

I think you are right. Being recommended a book I've never heard about by some author I'v never heard of by some computer system, I'm probably gonna dismiss it. However, if I've seen it in a bookstore, read about it in a paper, heard a friend talk about it etc. then I might act on the recommendation.

Basically being exposed to something enough times. First time and a cursory look, most things don't look to exciting. This goes for everything. Movies, restaurants, gadgets..