Vickie Stringer pretty much invented the African American Urban Fiction romance genre. Nobody wanted to publish her first book, so she self published. She sold her first copies by hand, going into African American hair salons all over her area, letting people rad a chapter or two and paying whatever they felt like it was worth. The hairdressers would tell their clients all about the books, and then give the clients the contact information of Stringer so that they could get a copy. She did a lot of driving and footwork. She owns at least two publish companies that she started herself. She's amazing. Her book on self publishing and self promotion is called, "How to Succeed in the Publishing Game. I'm not a fan of urban fiction, but this is one if the best books about self promotion I've ever read.
The Internet is an awesome platform to start with, but I wouldn't just promote online. For over ten years, I worked in bookstores. When I worked for an I dependent, we were constantly getting calls from local authors, self published or small press authors or "midlist" authors from the big publishing houses. One of these authors was Barbara Kingsolver. She made calls to Borders and Barnes and Nobles all over the Southeastern US region. They all turned her down, but the local bookstores picked her up and let her host signings, book talks, writers workshops -- whatever. She's a big name now, and last I heard, she refuses to do any events for chain stores, no matter how much they offer.
I have a friend who is a published YA mystery, supernatural writer. She's won some awards, and she's published by a big house, but she's still firmly a midlist author. She wasn't nearly a big enough name to get signings and events in big bookstores across the country. So she contacted a few other writers in her genre who were in the same boat. Together, they made a book tour in several States, doing panel talks about writing and creativity. It got her good exposure.
When I worked at the libraries and public schools as a media specialist, I was frequently fielding calls from children's book authors who wanted to host storytelling, writer's workshop or other events at the school. I took several up on their offers.
I am a presenter at gaming and sci fi conventions. I focus on education mostly, but there are oodles if authors who go around the country to all of these events all year long. They do big cons like GenCon and little tiny local conventions in small towns. They usually give writing advice. Sometimes they offer to critique the work of aspiring authors. They talk about how to get published or how to do book promotions. They get opportunity to meet other authors in the field and network. Sometimes a big name drops in to visit or give a talk. As a presenter, if you behave and the big name guys aren't jerks, they will treat you like a fellow writer instead of a fan. Sometimes they may ask for a copy of your book. I know newbie authors who got big name authors to recommend their books on the big authors own blog. You also get free entry into the conventions and you can wander around wherever you like when you aren't speaking. It's pretty sweet. Its my personal favorite haunt.
It takes time and money. But the payoff is pretty good. Also, check out Kickstarter. People are getting their tours and promotional costs funded. Of course, many people have dud projects because they don't know how to promote their Kickstarter project. Personally, I'm going to try to get published by this small local house I found. They get the funds to publish your book on Kickstarter and they handle the promotion side of that. They also handle contacting bookstores and other markets for you, but I'd still suggest pulling your own hustle at the same time.
Your online presence should be one of many promotional tools in your box. The more tools you use, the more you get your name out there.
But I can't be the only one!
It was a first for me, and incredibly invasive. And fruitless. If I'd have been inclined to take a peek at the book just because Support Your Fellow AWers, that would have slammed the door on that. As it was, I wasn't inclined. I've muted her so I don't get her daily Scout requests in my feed, and when I do a clean up of my Follows, she'll be unfollowed. 
