1) It's absolutely free 2) You can add attachments 3) Once you have made a post you can edit it if you are a member 4) You can also delete your post so long as no-one has answered you yet 5) No-one else can use your username 6) We can tell if you are or are not a member. If time is very limited, members will be given priority 7) You can send and receive private messages to and from other people