I've been doing something like this in my ebooks, and I thought I'd provide some similar boilerplate content that you can use in your ebooks.
Independent authors need ways to promote. I agree with David that word of mouth is the best path for us indies. This might be off-putting to some, or even sound like begging. But publishing is changing and we must adapt and persevere. Am I ashamed to ask readers for help getting the word out about my books? Not at all! And you shouldn't be either. In fact, if enough of us indies start asking, we might instill a new default behavior in readership to write reviews at a much higher rate than they do now (Dead Dwarves Don't Dance has sold about 8,000 copies and gotten 37 reviews, or about a .4% review rate).
So, feel free to use the following boilerplate in your books (I put it at the end of my books). Use it as is, edit it, take snippets, add to it. Whatever. You'll probably want to change a few bits to align with your own genre/books.
Want to read the sequels sooner?
If you loved this book (or any other book) the best thing that you can do for the author is to help promote it.
The vast majority of independent authors also have full time jobs and earn only a few thousand dollars a year from our novels. Unfortunately, we do not have enough time to promote nor enough money to advertise. We just write our books, publish them, and then hope readers find and hopefully buy them. For most of us, that doesn't mean a lot of money unless we get lucky and sell 50,000 or more books (most of us don't sell anywhere near that).
So, the best advertising for us is our fans telling their friends and family about the books. For us, word of mouth is the best advertising. In the age of the internet, word of mouth includes reader reviews, Facebook, Twitter, blogs, forums, and so on.
Writers don't have the time to find and frequent each forum, blog, review site, and so on. But, collectively, our fans might know about a many such sites. And if you love a book, it's a great idea to mention it in one of those places.
But, why should readers shoulder the burden of promoting? Isn't that the job of the author?
Yes, it is.
But posting on forums, updating blogs, sending out emails, trying to get interviews and reviews on big websites, and so on takes a LOT of time. Every hour of promotion is one less precious hour the author has for writing the next book in the series you love.
An indie author's promotion efforts actually make it take longer for the next book to get into your hands.
Would you like the next book sooner?
Again, the very best way to help make that happen is to promote the book yourself. I'm not talking about being militant and getting into anyone's face, commanding them to buy the book. But there are a few simple things that can really help, and if enough readers do it, other people might be convinced to buy the book:
1. Write a review for the book on Amazon or Barnes & Noble, or wherever you bought it. Reviews don't have to be long, but you should mention a few things that you especially liked about the book so people who read your review can get a better idea of what it's like. You might say: "I really loved how this book merged magic and aliens into an exciting adventure story." See? Simple and short and it says something about the book.
2. Mention the book on your Facebook page with a link to an appropriate website. Quick and simple like: "I read this exciting book. Check it out: www.talesofzura.com."
3. Rate the book or post your review on Goodreads or similar sites (such as librarything.com, shelfari.com, books.google.com, anobii.com, weread.com, chapters.indigo.ca, revish.com, reader2.com).
4. Mention the book on appropriate forums where you are a member. You wouldn't post about a spy novel on a gardening forum, but you could post about a kid's outdoor adventure book on a Scout forum, for example.
5. Post your review on your own private blog. Sure, you might only have a dozen readers, but you could be the pebble that starts the avalanche of interest that would eventually help the author sell enough books to quit their day job (or maybe even turn it into a movie).
6. Tweet about the book.
I bet you're thinking "Sheesh! That sounds like a lot of work! I'm not going to do that!"
And, of course, you don't have to.
But if you don't, the book you love might not sell well. For us independent authors who don't get any advances or have publishers backing us, we have to pay attention to sales. Most of us aren't rich. If a book doesn't sell well, the author probably won't write any more like it. Instead, the author will write a different storyline or genre to see if those sell better. Or the author might stop writing books.
If there are a lot of sales of a book, an author is encouraged to write more like it.
So, if you love a book and have some spare time, write a review. And if you have more time, tweet or blog or like or Facebook or chat or whatever you feel comfortable with.
Who knows? If enough readers do that, authors might be able to quit their day jobs and write novels full time. You could get the next novel in your favorite series two to three times sooner!
Let me know what you think of this, and if you use it. And if it works!
PS: Don't forget about my Kickstarter project where you can get a signed poster of the cover to Dead Dwarves Don't Dance!