For the last year, electronics retailer Best Buy has been introducing personal shopping assistants and tailoring the layout of its stores in order to get more money out of the biggest-spending customers. That strategy is off to a rocky start it seems, as the company yesterday attributed it as the main cause of declining profits from the same quarter last year. For the quarter ended November 26, Best Buy reported $138 million in profit, down from $148 million the year before. Game sales also played a part in the profit slip, as the company said "strong consumer interest" in the Xbox 360 couldn't offset soft sales for existing platforms. Entertainment software sales declined somewhere in the low double digits, according to the company.