Marco’s argument is essentially one of market share. He views total number of users as the primary goal. He wants to target as large a percentage of the total iOS user base as possible. That’s a perfectly valid business model that has worked for many. And for a podcast app, I think it’s a smart way to go. But it’s not the only way to skin this cat.
There are millions of iOS users in the world. I only need a tiny fraction of the right users to be successful.
I guess what I’m saying is, take everything you read from other developers (including myself) with a grain of salt. There’s no one way to be successful at this thing. Different apps in different markets, with different audiences, command different business models. You need to think about how you want to monetize your app long before you start building it. Consider all the options carefully. But don’t dismiss any of them out of hand because of what one or two others have experienced.