One thing I find lacking is that it seems to mostly be used by english-speakers. So the one case where I'd be curious to use the social networking features, for non-English-lanuage literature, it falls flat. There's no equivalent to it that I know of for the German-language world (that people actually use), which is irksome, because I'd actually use the social networking features there (whereas for English literature I know what I like and don't care what other people read, I don't know German literature as well).
But not becoming terrible is a nice side-effect of this...it's not even a managed decline, it's just pottering along okay! But it is odd. I wonder what their high-level strategy as a business is.