I was going to a different question of the week, but this one was related to yeseterday's tip, so golly-gee-whiz, I'm going to do it instead.
What do you think of author's hiring publicists?
Like everything else related to the publishing side of writing, hiring a publicist is a business decision. You have to decide if the expense (the publicist) is going to be worth it. If you think the publicist will garner you some prime exposure which will increase your book sales to the point that royalties will stay cover his/her fee, then a publicist is worth it. They are the ones with the contacts, and they will make sure that your publicity does reach your demographics. A good publicist is worth every penny they charge -- but only if their great publicity results in sales.
However, if you are in a niche not served by traditional media, or if you are already reaching your demographic, or it's a fanatically loyal group familiar with you, you simply may not need one. An example would be if the person who invented Neopets wrote a book on the subject. Neopets has a website with millions (I don't think I'm exaggerating) of users. A simple banner ad on the main pages would probably suffice and nicely sell out an initial print run of 100,000.