I think whoever initiates the request should say Hello, otherwise they are just asking to be a friend to bring their friend tally up or who knows what.
Facebook really doesn't cut it for me. Out of the 90 friends I had at one time I noticed that only about 5 of them would actually update their day to day goings on and when I would post something only my aunt or one other friend would comment on it...the rest of the so called friends would more than likely not read it. I was very active in saying Hi to my friends and posting comments on their pics/videos/etc but once I saw a pattern emerging I got irritated and deleted all but 9 friends.
Facebook is sort of an ok social book, just very basic, there should be something better and a better way to managing friends. When I figure it out I will create it, just cannot put my finger on it at the moment.