The National Post (at least the on-line version) has a thought-provoking column on Led Zeppelin's recent concert and the band in general:
Susan Fast on the success of Led Zeppelin's reunion concert - Dec 18 2007
Fast is a professor of English & Cultural Studies at McMaster University. I don't completely agree that a rock band should be the focus of study for a university professor - but I'm tempted to attempt to acquire her book on the subject of Led Zeppelin. (On the other hand, I know most everything about the band's history and music - so I might not.)
Fast poses a rhetorical question in the following paragraph:
Led Zeppelin always controlled their exposure in the 1970’s — very few interviews, a dearth of information about the band on album covers, long intervals between tours, and a tendency for them, the press and fans to mythologize what little information did emerge. But is this model for success based on absence the only one available for Zeppelin, or does it merely uphold some myth about rock authenticity — and perhaps the very concept of authenticity itself — that needs to be reexamined?
My take is that although Led Zeppelin did control their exposure in terms of interviews as an example, this was not the 'model for success'. The success built on the series of astounding albums and live performances. Zeppelin didn't need to hob-nob with the press to sell albums and concert tickets. Zeppelin fans appreciate that this sets the band apart - but is not salient to why we listen.