I think this is one of those ideas that's gets progressively less attractive as you get into details. It takes a lot of time and thought to write a good book r

I think this is one of those ideas that's gets progressively less attractive as you get into details. It takes a lot of time and thought to write a good book review, and you don't get anything out of it (unlike spending time to post a well-worded Ask HN, or spending almost no time to post a link to something interesting). Most folks in a HN-like community don't have that time. If they even have time to read more than a few books a year... so they aren't going to spend hours perusing book review (which aren't actually of value themselves.. they just point to other things that will be valuable to buy then read...).