For those of you wondering why The Magazine is on iOS (first) and not a website, the answer is simple. Marco is just replicating the successful Instapaper business model:
http://www.quora.com/What-are-the-Readability-and-Instapaper...
http://www.quora.com/What-are-the-Readability-and-Instapaper...
And that word. I do not think it means what you think it means...
If all publications worked this way, Instapaper couldn't exist.
It is reminiscent of Microsoft's strategy tax. Making a product worse cause it may harm your other businesses.
The Instapaper model is much simpler... but it's clear Marco doesn't really like it much any more, since you only make money by selling the app once but it costs you to support those users forever. So "spend less than I make" eventually gets very difficult if sales trail off.
In this case, it's a free trial, which makes sense when it's the first issue! But don't be surprised if The Magazine switches to a free sample. That's especially worth noting if you're expecting to optimize for a free trial.
My point is that Marco doesn't have any expertise selling advertising, as many would like him to do, and does have a lot of experience selling through the App Store. He's just keeping the business model as constant as possible.