Amazon, Barnes & Noble, Google Books and Kobo have removed their links to web-based stores from the applications for the iPhones and iPads. In fact, Google Books has removed the whole application itself.

The booksellers removed their links in line with an edict issued earlier this year by Apple that demands all apps offering content for sale or subscription to do so through the App Store, and not through external links to the seller's web store. Moreover, following its usual money making policy Apple require a 30% commission from all such sales.

While the edict was to come to effect June 30, booksellers were not quick to follow the requirement and continued adding links.

On Monday Barnes & Noble's iPhone app's App Store listing was updated: "You can read any NOOK Book you have purchased on this updated NOOK for iPhone app, however the Shop link has been removed so to buy NOOK Books from your iPhone, open your Safari browser and go to nookbooks.com."

The new App listing for Kobo's app, updated on Saturday, reads: "We have removed the Kobo Store from within the application. You can continue to shop at our website." Amazon's Kindle listing, also updated on Monday, says: "This update removes the Kindle Store button from the app."