How I Use It
I have come to the conclusion (after initially being excited about this type of site several years ago) that it's optional for my students. Everyone keeps track of what they read in my classes in one form or another. We do projects about the books we read, discussions, writing, etc. Book Likes is an option for students when they want to write about books, but most prefer to use their regular blog.
Book Likes is a cool site - nice interface, easy to navigate - for tracking your reading, blogging about books, and sharing recommendations. It really focuses on the blog aspect (sharing ideas and opinions about books) which is nice. It's not a lot different from sites like Goodreads, though.
My students used (when this kind of site first came around) to be excited about their digital bookshelves, showing the growth in their reading and the record of their reviews. Today, however, some of them get into it and some do not. We all keep track of what we read in my classes, some of us digitally, some of us with a notebook, and some with index cards. For some, things like Book Likes are great, but for others it's a chore.