This week, the iPad app world is frantically sorting through some recent changes in its environment. Last Monday, Apple quietly altered its app approval policies in a way that will make publishers much happier. Specifically, Apple has relaxed control over whether apps can access content paid for outside of the App Store’s purchase APIs. The company has also allowed publishers to price however they want, both outside and inside of the app.

In the same week, FT.com released a subscription-based HTML5 web app intended for iPad users that bypasses Apple entirely, giving the publisher its own path to market that does not depend on or enrich Apple directly. The coincidence of these two events is not lost on most of us industry observers and is the topic of a Forrester report issued by my colleague Nick Thomas last Friday. In it, Nick explains why the FT’s move is probably the first of many such moves by the most recognized publishers, even with Apple’s newly announced policy reversal.

But while publishers figure out their next steps for their content apps, there’s one app that no one is talking about but I believe everyone should have their eye on. It’s the Amazon Kindle app. This app violates even Apple’s revised policies and will soon face a day of reckoning when Apple's June 30th deadline for compliance comes up. 

I don’t claim to know Amazon's plans, but I will claim to tell Amazon what it should do:

Brace for impact. What I'm about to say is going to make a lot of people angry, including some of the people at Google who are going to rightly point out that when they pre-briefed me on today's Google eBooks announcement, we never once discussed ad-supported reading.

Instead, they told me all about their plan to establish a set of tools that will offer eBooks to people looking for book information through Google's search engine. They explained that this will make it possible for the millions of people who conduct book-related searches every day to have easy access to 3 million books -- some out of copyright, some out of print but under copyright, and a full range of in-print titles including bestsellers. They also described how independent booksellers will be able to use the same set of web-based commerce and reading tools to build their own branded eBook stores to finally extend their brick-and-mortar customer relationships into the digital space.

Since then, I've spoken to half a dozen reporters who were also pre-briefed and they have all had a similar set of questions: can Google compete against Amazon (no, but it can compete against Barnes & Noble), is it too late to make a dent in a mature market (no, less than 10% of online adults in the US read eBooks, there's plenty of room to grow), is Google's cloud-based strategy unique (yes and no, it supports all devices except the Kindle, but the Kindle platform actually supports as many devices as Google will). 

Consider it an inauguration of sorts, a celebration of the eBook industry becoming a member of the major media club just as digital music and online video have before them. When you influence a billion dollars, people have to take you seriously. In the book business, it means that traditional publishers can no longer live in deny-and-delay mode; meanwhile, digital publishers get invited to better parties and people in other media businesses like TV and magazines look over and wonder if they could cut a slice of this new pie just for them.

To honor the occasion, we have just published our five-year forecast for eBooks in the US for Forrester clients. The punchline is this: 2010 will end with $966 million in eBooks sold to consumers. By 2015, the industry will have nearly tripled to almost $3 billion, a point at which the industry will be forever altered.

Right now, the number to track – and the one that determines how many eBooks will sell – is the percent of a consumer’s books that are bought and consumed digitally. To get at this number, we have to understand how people get books today. Did you know that the two most common ways people get books today is borrowing them from a friend or getting them from the library? Evidently content – at least in the book business – is already quite free, even without the help of digital.

It was a surprising weekend for those of us who had naively imagined that after crossing the River iPad, we might actually get some Elysian rest. But, alas, the fates conspired against us and handed us the curious case of Amazon vs. Macmillan. Or Macmillan vs. Amazon?

For those who actually took the weekend off, let me summarize what happened. John Sargeant, the CEO of Macmillan Books, gave Amazon a wee-bit of an ultimatum: switch from a wholesale sell-through model, where Amazon buys digital books at a fixed wholesale rate and then can choose to sell those books at whatever price it deems appropriate (even at a loss, as it does with $9.99 bestsellers), to an agency model, where Amazon agrees to sell at a price set by the publisher in exchange for a 30% agency fee. Sargeant explained to Amazon that if it did not agree to the switch, Macmillan Books would make its eBooks subject to significant "windowing" wherein new books are held back from the digital store for some period, say six months, while hardback books are sold in stores and possibly, digital copies are sold through the iPad at $14.99.

This is more detail than we usually know about a negotiation like this because of what happened next. Sargeant got off of a plane on Friday only to discover that Amazon had responded by pulling all Macmillan books from the Kindle store as well as from Amazon.com. He then decided to make it clear to the industry (and his authors) that this drastic action was Amazon's fault, in a paid advertisement in a special Sunday edition of Publishers Lunch.