Less than a week has passed since Apple unveiled the iPad and its new e-book reading software, but it seems that the device is already disrupting the publishing market. This past weekend, publishing house Macmillan and online retailer Amazon sparred over the price of e-books.

The dispute began in behind-the-scenes conversations between the two companies, then spilled over into the public on Friday evening when Amazon removed the ability to buy all of Macmillan’s titles—both electronic and paper versions—from its site. Third-party vendors who operate through Amazon still had the titles for sale.

via Amazon and Macmillan fence over e-book pricing | Entertainment & HDTV | Playlist | Macworld.