from wikipedia:
The first 10 tracks were played on radio station network Triple M in Australia 9 pm Monday 3rd and again at 1 pm on Tuesday. Those tracks can now be previewed along with interviews with Angus and Brian on the Triple M website.
With the North American release of Black Ice on October 20th 2008, Columbia Records and Walmart created "Rock Again AC/DC Stores" with the album Black Ice holding centre stage. It was the first time in the history of Walmart that such a large area of floor space was designated to celebrate the release of a new album. In October 2008, MTV along with Wal Mart and Columbia Records created "AC/DC Rock Band Stores" in New York, at Times Square, and Los Angeles. "Black Ice" trucks were also dispatched on the streets of these two cities after the release of Black Ice, playing AC/DC music aloud and making various stops each day to sell merchandise.
And IIRC, AC/DC did shows in key-cities to promote the album.
I don't know... but I think that Wal-Mart deals are worth the risk.