iMore:

Apple has introduced a new cancellation feature for digital content in several European countries, including the UK, Germany, and France. The new policy allows customers in applicable countries to essentially “return” digital purchases from iTunes, including apps, music, and books, for a refund within 14 days of purchase.

For those of you who want to ask, “When is this coming to the US/Canada?”, keep in mind this is mandated by Europe wide consumer protection policies and directives. It may never be available to those of us in the US and Canada.