Books and albums have had official release dates for years. Used to be that if you wanted to be among the first to read that book or hear that album, you made time to go to the store on that Tuesday. (Why are release dates always Tuesday, by the way? Anyone?)
Now thanks to internet pre-orders, you can have the book or album shipped to you, scheduled to arrive on its day of release. Or if you have a Kindle, you can have the book appear on your device as soon as it's available for purchase. I woke up this morning and found the next book in my all-time favorite fantasy series, Elizabeth Moon's Kings of the North, ready to read on my Kindle.
This process hasn't completely killed the tradition of going to the store on release day, though, as anybody who has ever attended a Harry Potter midnight release party knows. It's become an optional, socially-intensive way of acquiring a highly-anticipated book or album. We have the no-effort way, in which it comes to you, and we have the maximal effort way in which we make a big production out of the acquisition. Either way, there's something wonderful about waiting for that piece of media you want, and devouring it on the first day you can get it.