"At" vs. "On" and What it Means for the iTunes Application Store

Lonely Sandwich talking about how prepositions affect the perception of the App Store:

I could say I bought a song on iTunes, but when I speak of it like that, I think of iTunes as more of a network for content rather than an outlet, much in the same way I’d say I saw 30 Rock on NBC or heard my favorite song on my favorite radio station. So does this mean that Apple likes to think of its iTunes Stores as networks? And if the iTunes App Store is a network rather than a retail outlet, what does that make the apps it sells? And herein lies the real question: is an app a product or is it content?

Only extreme nerds think about stuff like this. Hence why I find it interesting :-)