What You Should Know Before Publishing an Ebook

The  following summary highlights the key points from a major survey by Mark Coker of SW published on his Smashwords blog:

1. Ebook Sales Conform to a Power Curve
2. Most books don't sell well, but those that do sell well sell really well. This finding wasn't a surprise. Just as in traditional publishing, very few books become bestsellers.
3. Viva Long Form Reading: Longer Books Sell Better
4. For the second year running, we found definitive evidence that ebook readers - voting with their Dollars, Euros, Pounds, Krone, Krona and Koruna - overwhelmingly prefer longer books over shorter books.
5. Shorter Book Titles Appear to Have Slight Sales Advantage
6. How Indie Authors are Pricing Their Books: $2.99 is the Most Common Price Point
7. How Price Impacts Unit Sales Volume: Lower Priced Books (usually) Sell More Copies
8. The Yield Graph: Is $3.99 the New $2.99?
9. One surprising finding is that, on average, $3.99 books sold more units than $2.99 books, and more units than any other price except FREE.

Survey taken from 120,000 indie ebooks. 

P.S. Here's my two cents: You've got to SELL your books, NOT give them away.