Like, I imagine, a lot of writers/musicians/artists I often get messages from very nice people interested in helping me out, asking how best to go about it. For any writer, the answer is going to be: go to a store (in meat space or on line-- doesn't matter which) and spend actual money on a new (not used) book. There's nothing wrong with not doing that, but if you really do want to help the author, and influence whether or not more books by that author will see the light of day, helping the book is the way to do it, and buying the book is the way to do that. If you're really keen, you can encourage others to do the same. Go ahead then, philauthropists, show me what you got.