It used to be that reviews were limited to the literary pages of our weekend newspapers. The books were often put forward by publicists, and the reviews were written by editor-appointed experts.
Then came Amazon!
Amazon allowed us all to be reviewers, and we loved it. Giving us the opportunity to rate the books we bought made us feel close to this company - the website was ours, we were contributing to it. Of course, some authors tried to create fake reviews, pumping up their book's assets. And rivals went at each other's tomes, tearing apart their research and writing style. Reviews became suspect - at least for the wary among us. 
And then came other review sites - some from bloggers with a love of a particular genre, others simply giving readers a chance to share the books that brought pleasure and pain. has probably been the most successful so far, it hit 10 million users today. I love Goodreads, it lets me, the reader, share my point of view and read the thoughts of others, often helping me discern why a novel didn't particularly thrill. is a little older and, unsurprisingly, more librarian. In addition to reviews, the site allows you to input ISBNs of the books you own so you can display the book covers to other readers. A strange concept - I found it a little revealing to see my books on the shelf and couldn't help but wonder what they said about me. You also feel a strange connection with those who own the same ancient titles you have dragged through decades of house moves. is newer to the game. The site was recently bought by Sainsburys and aims to sell books. But rather than promote books in the Amazonian fashion - 'people who bought this also bought...', Anobii asks you to categorise the novels into topics such as 'books to read in a day' or 'books to make you think'.
I am sure there are other sites asking for our point of view, but there are only so many hours in the day - much of our free time has to be left for reading.
So where, Dear Reader, do you leave your mark? Which website do you favour when it comes to leaving your very own point of view?