"The growing clout of Wal-Mart and the other big discount chains ? they now often account for more than 50 percent of the sales of a best-selling album, more than 40 percent for a best-selling book, and more than 60 percent for a best-selling DVD -- has bent American popular culture toward the tastes of their relatively traditionalist customers...But with the chains' power has come criticism from authors, musicians and civil liberties groups who argue that the stores are in effect censoring and homogenizing popular culture. The discounters and price clubs typically carry an assortment of fewer than a thousand books, videos and albums, and they are far more ruthless than specialized stores about returning goods if they fail to meet a minimum threshold of weekly sales."