The legendary British Australian rock band AC/DC is one of the few holdouts when it comes to selling music through the iTunes record store, a stand the group has taken in part because it refuses to sell individual songs as singles — “We don’t make singles, we make albums,” says guitarist Angus Young — and Apple won’t let the band restrict its iTunes sales to just albums. That’s why its new album, Black Ice, is exclusively being sold through Wal-Mart stores, and it may also have something to do with the fact that the record has been topping the BitTorrent download charts as well.

According to TorrentFreak, just five days after the album was leaked on BitTorrent it had already been downloaded 400,000 times. Download-tracking firm Big Champagne said that in the first week it was available (the leak occurred on October 7, and the official release was on October 20) it was being downloaded about 100,000 times a day. If that rate continued — and there’s no reason to think that it hasn’t — then the album was downloaded more than a million times before it went on sale.

Has that affected physical sales of the record? There are only a couple of days worth of statistics to go on, and those are estimates, but it doesn’t appear to have hurt CD sales through Wal-Mart. According to Billboard magazine, sources said that close to 200,000 copies of Black Ice sold on the first day alone, and music-industry tip sheet Hits Daily Double said that based on first and second-day sales, the album could sell as many as 800,000 copies in its first week. That would make the record the biggest seller for record label Sony BMG in more than two years.

Demand for AC/DC’s music no doubt has something to do with the fact that the band — which has sold more albums than anyone but The Beatles — hasn’t released a new record in about eight years. But it’s interesting to see that almost a million illegal downloads of Black Ice doesn’t seem to have hampered sales of the physical product at all.