Among most writers, especially with the smaller and independent publishing houses, the hot topic always seems to be promotion. And as many different ways as there are to promote a book, there are just as many promotion styles.
I've seen writers who join social networking sites and make everything they do about their current work. Someone posts congratulations to a mutual friend about their new grandchild, these aggressive promoters will post back, "Congrats! Oh, I just had a baby of my own, my new novel, blah blah blah. You can buy it from my website or at Amazon."
Now I'm not against blatant self-promotion. Often, you need to promote yourself or you won't sell books. I guess my objection is to that handful of individuals who feel that EVERYTHING is about their novel. Maybe to them it is, but to the rest of the world, not so much.
It would help if those types of promoters would occasionally post about something different. For instance, if they posted a status update on Facebook about something else interesting they were doing, maybe I would also become interested enough in them to think about checking out their book. If every post they do, however, just talks about the latest novel, it's not going to entice me to buy it.
The second type of promoters are my favorite. They'll post when they're working on a chapter, or even ask for an opinion on something. They'll post when their book first comes out, when there's a promotion, sale, contest, signing, etc., in other words, when there is a reason for posting, but the rest of the time they post about parts of their lives that are interesting and that fans might actually want to read about. For example, when they've gotten a new pet. Or visited some place exotic. Or even planted a garden. Posts that tell us something about the writer are a lot more likely to make me want to buy their book than posts that constantly tell me about their book.
The third type of book promoters are the overly humble and meek, the type who are afraid to mention they even have a book, listing it in their information section, posting about normal life things, but never posting when they do book signings, promotions, contests, or blogs. While this may make them feel better about using social networks to promote their work, it also doesn't do very much to promote. I completely understand not wanting to appear like a showoff or braggart, but there's little point in using social networks or even writer sites for promotion if you're too shy to promote.
Social networking sites such as Facebook, MySpace, Twitter, even Linked in, are good sites to post information about your works, and to give your potential audience a chance to know those things you want them to know about you, and maybe get a few more people interested in your work. It's a tedious process, and I'm guilty about not staying as on top of things as I should in this area, but in the end it can make a big difference to book sales.
That's not to say that on writer's/reader sites it isn't acceptable to post mostly about what you're working on, because the people who visit these sites tend to do so looking for information about books to read, or looking for others' perspectives on issues related to writing. I still think it's important to allow a small glimpse into your personal life if your goal is to get people interested in you as a writer.
In my opinion, a happy balance among the promotion types yields the best results. While the public doesn't need to know every time the writer uses the bathroom, the public may be interested in knowing the writer's favorite food, vacation spot, or television show, and revealing little tidbits of information may help increase sales, as long as the information is limited to those things that won't become a safety concern.