I think it's okay if not taken to extreme. There's a difference between writing a book review and writing a tweet. It's hard to say much in a tweet, but I'm in

I think it's okay if not taken to extreme. There's a difference between writing a book review and writing a tweet. It's hard to say much in a tweet, but I'm in favor of people writing book reviews. Also, posting a tweet linking to your book review seems fine? It's a good way to draw people into reading something longer when they take a real interest. A few people who read the book review might go on to read the book. Most won't, and that seems okay, as long as they're reading.