1) Nonfiction is easier to promote. Why?-You can easily relate it to something current like an event, a new study etc.
2) Publicity is time consuming.-Make sure you're able to devote the time. If you can't then hire someone who can. Publicity takes time and sometimes nothing comes of it, other times you can reap major benefits. It's all about time and persistence. This is something big to consider when one goes the self-publishing route. You will have to promote your book with a traditional publisher, but there may be more work involved on your end when you self-publish.
-In fact, for those familiar with publicity, there is some talk that a press release's role is evolving. I personally prefer to formulate a pitch. (Very much like a query). I consider a press release secondary. Something that quickly provides information for say an event, or quick facts one can use to get a quick background on a book or specific subject.
4) Not all methods work for everyone. You must try to find your built-in audience.
a) Let me give you an example. Say we have a MG author whose books focus on Greek mythology. The people this author should be targeting is not just the 8 to 12-year-old readers, but teachers, librarians and parents. The ones who have a say in what their child can and cannot read. These are the people who put the books in front of the children, the ones who stock them in the libraries. This can easily be done by sending a copy to school librarians, speaking with them and hosting presentations in the classrooms. For a MG author, an elementary or middle school already has their built in audience.
b) Now, for a nonfiction author whose book deals with the civil rights for African Americans and a famous case, an elementary or middle school is probably not the best audience. Instead his built in audience is within colleges. With that famous case he can target law schools and because of the intense historical aspect he can contact history departments. By promoting his books through speaking engagements you never know if a professor may want to use his book in a classroom. Those are instant book sales if each student in the class must purchase a copy. But that's not the main reason to host these events with colleges. Instead, it's merely a way to find readers who would be interested in the topic or topics he has written about. Just like a MG author shouldn't target a bunch of 21 something year olds with no kids for a middle grade book.
5) The traditional media is still viable.
-Many authors have taken to using bloggers as of late, most even believe it's easier than getting the traditional media. The traditional media, like TV, radio and print are still viable options. There are some who prefer to follow industry blogs, while others are still with traditional media. In order to reach both audiences one must seek to utilize both. Think about it. If you have something truly news worthy then the media will be interested. Let's take Jennifer L. Armentrout for example. Entangled Publishing has a whole publicity campaign going on online about Jennifer coming to Georgia and Florida this June. Sure, another author is coming to town. What's the big deal? Well, they're bringing along the book cover's Hungarian models, which have grown in popularity since they've been used on other book covers, actual magazines and even the company European Wax has them all over their promotional material. Within the literary world, this is buzz. This is so fun and out there that for traditional print or TV it could make for a fun human interest or community piece. It's just a matter of finding the right newsworthy aspect of whatever "news" you have to offer the media.