Nope, 12% in that case. The 27% figure assumes a reduction from the 30% rate virtually nobody pays. If you read Apple’s documentation, you’ll see that they say they will reduce their commission by 3%:
> Apple will reduce its commission by 3% on the price paid by the user, net of value-added taxes. This is a reduced rate that excludes value related to payment processing and related activities.
100% of the top 100 paid apps on the App Store pay the full tax. It's a progressive model, and the figure itself is arbitrary anyways. People want a more Mac-like distribution model, and Apple is reluctant to provide it because services are the only thing with wider margin than slave labor cellphones.
