Apple has finally started to enforce its in-app subscription rules and has seen a mass unlinking by content providers unwilling to give Apple the 30% cut of sales it demands.

The controversial new rules announced by Apple in February whereby Apple demanded a 30% share of all sales via e-reader apps on the iPad, iPodTouch and iPhone were supposed to come into effect on June 30. In the event there was a stay of execution, but as soon as the rules were enforced Google, Amazon, Barnes and Noble and the Canadian company Kobo removed the links that let users of Apple devices buy new titles directly.

Instead their Apple customers will need to make future purchases via the Safari web browser and face the inconvenience of having to upload the titles to their iPads etc as a second step.

The Wall Street Journal has also removed its subscription purchasing link in order to comply with Apple's regulations and last month the Financial Times launched its proprietary HTML5 app to circumvent the new rules. Kobo has now announced its intention to develop an HTML5 e-reader app.

So perhaps it won't be end users that lose out but rather Apple itself.