For me, if I have a choice between a box of cereal and a box of cereal with a premium inside, I'll always pick the premium. I'll send in boxtops to get the decoder ring. People love getting something extra, they love being engaged.
Self-publishing gives you myriad ways to engage the reader through bonus content. There are so many possibilities: previews of other books, interviews, anecdotes, background about characters or setting, links to resources. Say you're writing a historical mystery. What better way to give the reader a little something extra than linking to resources about the era or the subject matter, a Flickr stream of photos, a list of other books they might enjoy? How about an interview with your protagonist? How about an anecdote about your first flash of inspiration for the plot or the character? A scene that you cut, not because it was bad, but because it didn't quite fit with your pacing?
If you want to get really wild, you can go interactive: an Internet scavenger hunt, a treasure map, a contest. If you're clever and involved, the sky is really the limit.
How many times have you enjoyed a book and at the end wished it wasn't over or wanted to know what happened to a character or wanted to just keep that little bit of magic going? How many times did you want to tell somebody else about the great book you just read or leave a note to the author? You can provide that opportunity to your readers with every book or story you put out.
Bonus content serves three purposes: it engages your reader, it gives your reader a sense of greater value, and it gives you a chance to further market your work. At the very least, every one of your books should have an "About" or "Follow Me" section, where you can list your websites, blogs, Twitter, Facebook, or other social media sites. Make it easy for the reader to engage with you, to seek you out, to find your other work.
Practical Example: What am I doing? This week I'm publishing four short stories via Smashwords and Kindle. These aren't just thrown together to get them out, they're my four best short stories. Initially I'm going to give two away for free and price two at 99 cents, just to get a feel for how free stories affects pay stories. I have three goals: I want people to be able to get a feel for my writing for free, and I want to generate a buzz for the novels that will be coming out -- four full-length (over 325-page) novels over the next three months -- and I want people to follow me on Twitter and on my blogs.
So for each short story the package will include: The short story, a little "About the Story" lagniappe, a preview package of the next two novels (a cover, blurb, first chapter of each), and a page with all my personal "Follow Me" information.
Example: "Sticks Like Bones" will include this lagniappe:
About the Story: Sticks Like Bones
This was written on spec for an anthology that folded before publication. I mention that because it’s the only story I’ve ever written where I wrote TO a concept instead of having an idea show up at the top of the cellar stairs demanding to be let out.
I find the French Quarter a fascinating place, almost like a slice of elsewhere that fell through a rip in the fabric of here. There is such a feeling of weight to it, but it’s always shedding itself, in brick dust and loose nails, bits of crumbling slate from roofs and flakes of paint. It’s a reminder that time exacts a price, that decay keeps running through everything even as we live our lives without paying it heed.
The places described in the story are a mix of the real and imagined. The oddest thing for me is that even though the French Quarter is a cleanly laid-out rectangle, I always get lost if I’m walking alone, almost as if the layout changes around me, like some multi-dimensional funhouse. Suffice to say, I no longer walk without a companion.
Following that, I'll give the cover for Running Red and this blurb:
Jesse Stone has been running the night roads for 150 years, preying on humanity for survival, but he still feels an ache from the empty place where his soul was torn away. Other vampires – an ex-SS soldier, a fanatical tent preacher, an Aztec biker – have been gathering an army for an assault on humanity. Now Jesse must lead a rag-tag band of humans against the others, in a last-ditch attempt to find redemption…
Look for Running Red, coming soon.
I'll follow that with the first chapter of Running Red and the preview package for Darker By Degree.
Then I'll finish it up with a "Follow Me" page that lists every place I can be found.
Easy-peasy. With a hour or so of extra work, hopefully I've given the reader that little something extra, I've piqued their interest, and I've given them further reason to seek me out.
What lagniappe can you give your readers?