Conversely, The Deposed King, I know a couple somebodies who have several books on Kindle who haven't had much success at all, despite being definitely readable, and making an attempt at advertising.
You know my Falon books are pretty readable and yet I have very few customers. And that's with a high functioning sci-fi series popping up right beside them on the search lists.
That tells me that my books can't just be readable, they have to have something else. Like my brother says, I have to be able to answer the question: why would the reader want to read this book?
And sure part of it is reaching your audience. But the other part is being good enough that when you get that look, you start snowballing down hill, growing your audience by leaps and bounds.
And sure there are books that aren't getting the look they deserve. But on the other hand there are books like my Falon series that get the look and then are politely set to the side. There's nothing 'wrong' with it, there's just nothing calling out for people to start buying it in job lots. Plus like I said. It can take months for a book to catch on, and I assume its only going to get more competitive.
My advice if your friend has difficulty getting a look. Is do another editing pass for nits, get a new cover and see what is what. The other thing you can do is write more books. The more you write the more spots you have up on the search engines for those who are interested to come and find you. If on the other hand they had 20+ sales a day for a few days in a few and things dropped off... well you got your look. That doesn't mean give up. It just means you need to do more.
If you haven't got even that high on the sales front all I can say is keep after it. Lots of people and smashing it out of the ball park. And unlike in the days of the dead tree, where if you have one failure of a performer you are forever consigned to the bottom of the charts because the bookstores won't buy enough copies of your novel to ever have the potential of high sales, unless you change your name and start over, here with e-books, we don't have that problem. Just keep banging them out.
The Deposed King