I read dozens of tech and well over a hundred fictional books per year and have been doing so since the mid 90's. For a time, these books were purchased hardcopy from B&N, and then hardcopy from Amazon, but since 2007 or so - they've all been kindle e-books. There are three kindles in the house. An ancient Kindle DX, and two smaller kindles that the kids borrow.
Given the above, and my strong familiarity with the amazon website, I have the following recommendations for authors looking to sell to readers like me:
1) Release E-Book at the same time as the physical book. I generally have a vague memory of all the books I've looked at because they seemed interesting and then for whatever reason did not purchase. This means that I'll generally only investigate a book once and only once. If the kindle version isn't available when I visit, odds are I'm not coming back to purchase later. Also, authors that regularly release physical books months before the kindle versions or which may not release kindle versions at all, well I keep an naughty list for them and their books do not get bought.
2) If it's a fiction book, it must be at least 200 pages. I don't read novella's or short stories, and I'm not buying six 100 page books that should have been one large book....even if the pricing of each is only $0.99 - just not going to happen. I'll wait for a combined version of all six books as one instead.
3) If it's a fiction book, it must already have at least 3 reviews of score 4 or higher. Unless a book is personally recommended to me or I'm familiar already with an author, I don't read unreviewed books. In general, I also skip all books that are rated 3 or lower and tend to only look at 4 and 5 star rated books. Reviews matter - I read most of them and I'm much likelier to buy a book if nearly all the reviews are 5 stars or if many of the reviews are detailed about why they did/did not like the book.
4) Write a good book description. Just a few lines describing it at a very high level. Don't give me a plot summary. I don't care about the characters. I want to know why this is a good book...that's it. If it's a good book and the reviews indicate it's something I'd like to read, I'll buy it and learn everything else on my own. Few things make me run away from a book faster than seeing a detailed plot summary in the book description.
5) Price your book well. I know that writing a book is a ton of effort and you need to put food on the table for your family...I'm not going to try to cheat out good authors. But, there is a limit on what any book is worth. If it's a tech book, you're unlikely to get me to pay more than $30. For most tech books, $15 is my sweet spot. For fictional books, unless you're my favorite author and have released a book that I've been waiting for, I'm just not going to pay more than $9.99 - really. If you're a new author, I'm probably not going to pay more than $2.99. And even for authors that I might be familiar with and have read one or two books from, I'm unlikely to pay more than $4.99 - There are dozens of new books coming out every week on Amazon, many of them priced between $0.99 - $3, and while most of them are not great....I'd much rather read 2 riskier books for $2 each than 1 sure-fire book for $6. Why? Because most books are forgettable...like tv shows...I'm calculating how much I have to pay per hour it takes me to read. If you want a higher price, I'm going to look at how long the book is and how many days it is likely to take me to read it. I'll pay a reasonable premium for an extremely long book (600-800 pages).
6) Don't change publishers or make major revisions to the ebook after you've listed it. Nothing annoys me more than authors that must re-release their books because their publishing arrangements change or major revisions have been made. Amazon suggests that I buy a book that I've already purchased (somehow two entries get created in their DB for the book)...and even if it isn't the authors fault, it makes me feel like someone was trying to scam me.
