Staples says it does nearly half of its business online these days, and by the end of next year, there will be fewer physical locations in competition with that. America's largest office-supply chain today announced that it will close up to 225 stores in North America by the end of 2015; Bloomberg points out that's 12% of its 1,846 locations on the continent. Some 42 North American locations were closed last year. The move comes as part of a plan to save about $500 million annually by 2015. The retailer shared that fiscal Q1 sales will be down year-over-year; that's the fifth straight quarterly decline.