Thinking about my own promotional efforts, I realized that there are four primary benefits I receive from them, one or more of which are present in each promotion. They are:
1. Publicity
Name recognition is such a valuable asset that it can be helpful to do promotional activities solely for the purpose of getting your name out in front of people. Whether you attempt to get yourself, or your book, mentioned in a magazine or newspaper article, or you create a humorous or inspiring video that you hope will go viral, publicity give you either credibility, or recognizability, or both.
One way to get your name and writing circulating on the web is to give it away with no strings (or opt-in) attached. Article marketing is a good example of this. Of course, free content usually contains a short bio, contact information, some basics about your book or business, and an opt-in offer to entice the
reader to come to your website and learn more. Freebies definitely earn their keep.
In general, most promotion has a publicity element to it, as whatever you do has at least your name, book title, or product information on it.
2. Relationship Building
While you want to constantly be promoting yourself and your book, you don't want every tweet, or blog post, or video to be selling, selling, selling. You would quickly lose most of your potential readers that way.
Relationship building is a time honored form of promotion, and blogging is its leader online. The beauty of relationship building promotional activities is that what you're writing or talking about can be focused directly on your book, or its subject, so there can be a direct relationship between your book and the promotional activity, without there being any direct selling.
Yet relationship building goes beyond talking about your book, and touches on the personal. It's a chance for people to get to "know, like and trust" you, not only as an author, and expert in your field, but as a person. Twitter is exceptional at blending the personal and professional, while allowing you to connect with your readers in real time.