-Authors get up to 70%, as opposed to 5-15% -Far less trees are killed
-Eliminates the role of the publisher / physical distribution channel, which claimed the lion's share of the profits without adding creative value
-Marginal cost of distributing an extra book is on the order of cents
I've not read a hardcover book since getting a Kindle.
But it wasn't true in music---the industry was vertically integrated.
For instance Virgin Megastore sold records in London, and world wide.
Virgin Music produced those records.
Virgin Music Group (known in the US as EMI) handled distribution of the records to out-of-chain companies.
Virgin even broadcast under the label Virgin Radio, and sponsored festivals such as the V-Festival.
That's just one example, but the whole industry was integrated to various degrees.