Brand selection - the number of alternative brands of a particular product - is a double-edged sword in that on the one hand it increases rivalry and so stimulates price competition but on the other hand it causes consumers to be poorly informed and thus vulnerable to exploitation and so dampens price competition. This phenomenon is demonstrated analytically and empirically, with analytical work based on Hotelling's unit market line. Using price dispersion as a measure of the state of price competition, it is shown that a widening in price dispersion, that is, a lessening of price competition, arises from an increase in brand selection. Any increase in the number of alternative brands on offer (brand selection) causes an increase in 'DIF-ness' (Distortion in Information Function) which in turn causes an increase in price dispersion (a lessening of price competition). The phenomenon is demonstrated empirically through a small survey of household beverages.