Best Buy (BBY) reported a surprise sales slump in its key holiday shopping season. Same-store sales declined 0.8% in the fourth quarter, the company said Tuesday. Wall Street had hoped for a 0.2% increase after two straight quarters of positive growth. "Our data sources show our overall market share was at least flat, pointing to slightly softer customer demand for our industry during the holiday quarter," Best Buy CEO Corie Barry said in the release. It expects first quarter same-store sales to return ...