It has long been true in the book industry that publishers hold back paperback editions for about a year after they release the hardback edition. Ebooks are now receiving the same treatment by many publishers. The theory is that paperback and ebook editions would cannibalize hardcover sales if they were made available at the same time. In other words, publishers are banking on the idea that you will buy the hardcover because you can't wait for the format you really want.
I've read many opinions on the subject, and most of them focus on the politics involved between the publishers, agents, authors, and the retail sales channels. I think they are all missing the point, or perhaps just I am. Almost no one focuses on the reader, except to talk about how the current strategy manipulates buyers into paying a premium for the hardcover edition by preying on their impatience. That strategy has never worked on me, so perhaps that is why my thoughts in this subject have a different focus.
Realistically, the only difference between the three book formats is the packaging and, artificially, the timing. There is no practical reason why all three could not be released at the same time. The content is the same in all of the editions.
Imagine what would happen if the publisher released all of the editions together? You would be able to buy the book in your preferred format along with everyone else. Good grief, that almost sounds like good customer service!
Instead, publishers create artificial scarcity by releasing the other editions long after the hardcover has come out. They want you to pay extra money for the edition you don't really want just so you can have the convenience of reading the book earlier. That kind of manipulation just annoys me.
Now, someone might point out that Logical Expressions has not made ebook editions of all our books available yet. That has nothing to do with manipulation and everything to do with me having the time to do the ebook conversions!
If you want to see the book industry change these manipulative practices, you have it in your power to do so. You can vote with your wallet. The first step is to refuse to buy a book in a format you don't want. The second is to specifically request the book in the format you DO want.
Publishers will only continue the current practices as long as those practices continue to work. Manipulation requires two participants: the manipulator and someone willing to be manipulated.