Best Buy Co., the nation's largest consumer-electronics retailer, said its fiscal third-quarter earnings jumped to $54.4 million, or 52 cents a share, from $26.4 million, or 29 cents, a year ago, as revenue climbed 18% to $2.49 billion. The results beat analyst forecasts by two cents. Sales at stores open at least a year jumped 12%. Prices for newer products, such as digital cameras and DVD, have fallen in the last year, spurring consumer demand. Best Buy has also worked to better manage inventory so it's not left with too much merchandise it has to mark down.