Very smart, and I suspect soon to become pretty standard. It creates a buzz for the new Arcade Fire album, and it rewards people who pre-order their new album The Suburbs.

The gig is on the 7th July, tickets go on general sale on the 1st, but people pre-ordering the album by midnight on the 24th June get to buy tickets between the 28th and 30th.

It gives fans a reason to buy the album, rather than get it illegally, and it gives them a nice reward. Note that you have to buy the tickets for the gig, and that pre-orderers of the album aren't guaranteed that they'll be able to get tickets.
[null, {"document_url": "http://digital-examples.blogspot.com/2010/06/arcade-fire-secret-gig-in-london-for.html", "unformatted_src": "http://2.bp.blogspot.com/_RHJCq8Jes1s/TCHx9AtSzdI/AAAAAAAABZc/oWx6GmnKtvw/s320/TheSuburbs_Artwork_cover1.jpg", "src": "http://2.bp.blogspot.com/_RHJCq8Jes1s/TCHx9AtSzdI/AAAAAAAABZc/oWx6GmnKtvw/s320/TheSuburbs_Artwork_cover1.jpg", "formatted_filename": "TheSuburbs Artwork cover"}, null, null, {"document_url": "http://digital-examples.blogspot.com/2010/06/arcade-fire-secret-gig-in-london-for.html", "unformatted_src": "http://www.linkwithin.com/pixel.png", "src": "http://www.linkwithin.com/pixel.png", "formatted_filename": "pixel", "alt_text": "Related Posts with Thumbnails"}, null, null, {"document_url": "http://digital-examples.blogspot.com/2010/06/arcade-fire-secret-gig-in-london-for.html", "unformatted_src": "//bp1.blogger.com/_RHJCq8Jes1s/SJhTQh3dUGI/AAAAAAAAAPM/o-6L4pWWSbM/S220-s80/Guitar.jpg", "src": "http://bp1.blogger.com/_RHJCq8Jes1s/SJhTQh3dUGI/AAAAAAAAAPM/o-6L4pWWSbM/S220-s80/Guitar.jpg", "formatted_filename": "Guitar", "alt_text": "My photo", "rendered_width": 80, "rendered_height": 60}, null, null, null, null, null, null, null]