On-demand Media: Is YouTube a destination?

When YouTube started, it was hardly a destination, even for its users. It was a hosting service: they let you save your videos and share them (if you wanted) with your friends, for free. Users didn't go to the YouTube portal; they just followed 'deep' links on an email, watched a clip and then left (or, even less engaging, watched a clip on a player embedded in someone else's site).

Although today YouTube continues to be a hosting service, it has also managed to start becoming a destination in its own right. I don't know to what extent the audiences that use it in one way overlap with those that use it in the other, or how large each is (if you know, please drop me a line), but it's clear that for many people visiting the YouTube home page has become a routine.

That is no small achievement. How did YouTube do it?

As an outsider, I venture this explanation: Back when people were using YouTube only as a hosting service, its owners did all they could to make its content pages (i.e. the pages surrounding individual clips) into aggregates by offering plenty of promotional links to more content on the sidebars next to each clip. Although users weren't looking for an aggregate (i.e. a destination), many found one in the sidebars and got a taste of the YouTube aggregation experience. Because the experience was always heavily branded users began to associate it with the YouTube brand (as I've argued before, aggregation creates brands - not the other way around). Over time the experience became a practice, which itself (rather than the specific video clips it relies on) became an object of desire. Only at this point did people start visiting the YouTube front page. Finally, the practice itself (as opposed to the clips) became a word-of-mouth phenomenon, and then a household name.

I say all this without any evidence. Do you have any that would support or refute my account?