Best Buy, Inc. (NYSE: BBY) has gone shopping across the pond, and will be spending about $2.1 billion in cash to purchase 50% of the UK's Carphone Warehouse mobile telephone retailer. Best Buy is signaling to the retailer world that it thinks mobile is the place to be, after it committed to expanding mobile market share here in the U.S. just recently in a large way.

This multi-billion commitment to Carphone Warehouse will allow the European retailer to pay down debt and gets Best Buy a foothold in the European retail business in a pretty large and immediate way. Along with Wal-Mart Stores, Inc. (NYSE: WMT), U.S. retailers are seeking out ways to expand their footprints globally. Carphone Warehouse isn't just a small step in that direction, as it's one of Europe's largest mobile phone retailers.

Best Buy's revenues continue to soar on an annual basis, and this partnership should add to that amount significantly. While U.S. competitor Circuit City Stores, Inc. (NYSE: CC) has had nothing but troubles recently and is just hanging out in la-la land while delivering substandard results every quarter, Best Buy is going for the jugular -- still growing sales and taking market share in the U.S. and now in Europe. Can it be stopped? For now, there's no equal -- so, no.