Apple’s iPad was launched a few days ago and the war in the e-book arena quickly escalated.

Amazon has pulled all Macmillan books from its online store. Macmillan is a big publisher and includes publishing houses Henry Holt & Co., science fiction-focused Tor/Forge and the Tiffany of fiction, Farrar, Straus and Giroux.

It seems that Amazon and Macmillan were in disagreement as to the price of e-books sold for the Kindle. Amazon wants a price of $9.99 for Kindle e-books, but the publishers aren’t happy with this demand and would like, of course, to sell their e-books for higher prices.

Amazon could put a lot of pressure on publishers right up until Wednesday, the day of the iPad’s launch. Now the e-book arena has a set of different rules. Sure enough, the publishers didn’t wait. Five publishers were announced to be working with Apple; Macmillan is one of them.

Amazon still has dangerous ammunition, though: all formats of Macmillan books are now unavailable for purchase from the online giant. This can be very bad for the publisher.

It’s hard to predict who will win this battle. After all, there are quite a few online retailers that sell books. If a shopper is really eager to get a certain book, he will find it in a myriad of shops. On the other hand, Amazon has very effective marketing tactics, and buyers may simply be tempted to buy a different book or product. It seems that cooperation is in the interest of both sides and that a compromise will be reached, eventually.

In the mean time, let’s hope that good, fierce competition between different platforms will benefit us, the clients.