Something about what you have written doesn't sit right with me.
If Macmillan decided not to use the iBookStore and sell their ebooks on their own to the customer (the reader of the book), and all the other publishers saw that and thought, "Hey, that's a good idea", that would lead to the destruction of what you have called the publisher-retailer market.
Is it anti-competitive to choose not to participate in a market? It doesn't seem that way to me.
If I produce a product, am I not free to choose (or create) a market to sell this product? And can I not withdraw from that market whenever I see fit?
You can withdraw from the market, of course. It's not anti-competitive to destroy a market by rendering it redundant. But that's not what is happening here.
If Macmillan decided not to use the iBookStore and sell their ebooks on their own to the customer (the reader of the book), and all the other publishers saw that and thought, "Hey, that's a good idea", that would lead to the destruction of what you have called the publisher-retailer market.
Is it anti-competitive to choose not to participate in a market? It doesn't seem that way to me.
If I produce a product, am I not free to choose (or create) a market to sell this product? And can I not withdraw from that market whenever I see fit?