Well, the point of the comment was the demonstrate that a 30% revenue cut is rather onerous through the thought experiment of what would happen if an additional one was placed.
That being said, existing services absolutely went through this sort of increase when customers wanting to use a service with a known pricing model, interacted with the service on this new platform: services that wanted to put their business on the App Store DID have to either add an additional 30% increase across the board, or (as mentioned in the end of the comment), treat App Store-acquired customers as 30%-less revenue generating. Again, from the customer's perspective, which I have repeatedly tried to convey, this is confusing and opaque. Notice that in none of my above comments do I ever lament app developers, and thus do not need a business 101 explanation. I am lamenting that Apple, through a combination of not just placing a large 30% cut, but additionally not giving developers the flexibility to either increase the price of the product by 30% on said platform, created an opaque situation where the customers appears as a lower-revenue generating customer to a business.
This was not imagined, it was discussed quite a bit in the space (especially when the MAC App Store appeared), where EXISTING apps, pre App Store, found themselves in the very unfortunate situation where they hoped people found the app not through the App Store.
