[horsawlarway]

If the regulation is smart (sometimes the EU does ok with tech regulation, sometimes they fail miserably) then it's not about picking a number.

The number is never the issue. The issue is that apple has artificially blocked any competing channels from distributing to iOS.

I don't believe they should be allowed to have a legal monopoly on app distribution. In fact, I'd go as far as the ruling for IE with Microsoft around basically the same issue but for web apps -

Not only are you not allowed a legal monopoly on app distribution, you MUST ask the user which app distribution methods they'd like to enable.