If you are an author and you only link to A**zon on your website, booksellers will hate you. Really.
If you go to a store, get a bunch of book recommendations and then go buy them online? You might as well walk up to the manager, slap her, and tell her that you hope her store closes. Yeah. That's how big a jerk you are.
If you go to a booksigning at your local independent bookstore, and you don't buy a book? YOU ARE ROBBING THEM.
If you are an author yourself, set a good example for crying out loud. Shop at bricks-and-mortar bookstores and link to indiebound or an indie store on your website. When you try to befriend booksellers, a good way to do it is by actually buying the books they recommend. When you go to "support a friend" at a signing, try actually being supportive by BUYING A BOOK.