Books not so much. It's worked for me so far.
But the other morning I awoke to this on my Goodreads author dashboard:
It's the new recommendations feature. In the large gray square it points out that I've rated only one book (the Stephen Fry reading Harry Potter audio set; Goodreads treats books and audio books the same), and to the right it tells me that I need to rate at least 19 more (twenty being apparently the minimum threshold) to get personalized recommendations from the site.
Maybe it would be different if I'd grown up with the everyone's-opinion-counts-equally-and-should-be-heard system, but I didn't. The hundred books on my virtual shelf are only a sample, a sliver of my reading life, the books I happened to catch sight of on my (real-life) bookcases in the past few months and thought, that's a good book, I should it to my Goodreads shelf. If I added all my P.G. Wodehouses, that be, like, another hundred books right there.
Besides, how do you rate a book you read years ago and remember fondly but suspect that rereading it now that you're an (ahem) older, wiser adult might change your view of it?
How do you rate books by fellow authors?
For that matter, how do you rate a book in the first place? I think I'm too close to them. I rate movies easily because I'm not in the movie industry. Does anyone expect George Lucas to rate films? (Actually, I have no idea. For all I know, he might.)
By the way, I like all the books on my Goodreads shelf. Why go to the effort of adding them otherwise?
Goodreads recommendations are a welcome feature, but I don't think that in itself will nudge me into assigning ratings. One thing might, however. It's not that "1" that sits in the large gray square above. It's the unintended grammar gaffe in it: "You've rated 1 books so far." That will drive me nuts in about a week, and I'll have to rate at least one book to change the "1" into a "2". Once I've done that, well...