Wal-Mart, which sells more DVDs than any other retailer, has been advertising on Pirate Bay, the Swedish-based company that indexes pirated movies available for illegal downloading on the Internet, Daily Variety disclosed today (Wednesday). The trade paper observed that in one instance, Wal-Mart's ad for The Simpsons DVD collection was served on the same page with search results showing how the same collection could be downloaded free. "While the ads encourage a legal behavior -- buying DVD's," Variety commented, "they support the site, which lists more than 130,000" illegal movie files.