Article from the New Yorker, nov. 2012.
The Grateful Dead occupy a curious spot in the canon. Their music has turned out to be extremely resilient, considering that they were primarily a live act and effectively ceased to exist seventeen years ago, when Garcia died, and that for many of the years prior to that (how many is just about the most debated question in Deadland) they were a weak incarnation of themselves. They made a lot of studio albums, but few memorable ones, and had just one Top Forty hit in thirty years, and not for lack of trying. Yet it’s probably safe to say that the Dead have more recorded music in circulation than any performing group in history. 
From their establishment, in 1965, to the death of Garcia, in 1995, they played 2,318 concerts, and more than two thousand of those are available in some form or another.
The band has released a hundred archival concert recordings, under various rubrics, but they also often (though not always) tolerated the taping of their concerts by people in the audience, as long as the tapes were traded, not sold.
As Garcia said, “Once we’re done with it, the audience can have it.”
http://www.newyorker.com/reporting/2012/11/26/121126fa_fact_paumgarten
