Colliding air masses within tornado alley make for exceptional conditions that allow for vigorously rising air, which is essential for thunderstorms. Storms in the Great Plains regularly reach 10 miles (16 kilometers) into the sky because of these conditions: 1  Winds pushing disparate air masses converge in tornado alley. 2  Colliding air, known as fronts, have nowhere to go, therefore they rise.
Apple's fiscal 2011 10-K report showed that the average size of an Apple Store has creeped up to 8,400 square feet per store, but Needham & Company analyst Charlie Wolf says that the retail stores are bulging at the seams and just aren't big enough.
The average store of the next most successful company in the United States, Tiffany & Co. (TIF), sold less than half that per square foot. In low-end department stores and supermarkets, sales per square foot were in many cases less than $100. Hancock Fabrics, a fabric retailer, brought in just $72 per square foot. Meanwhile, retailers with the most profitable stores brought in more than $1,000 per square foot. These are mostly high-end brands, selling much more expensive products. Based on the RetailSails report, 24/7 Wall St. identified the nine most successful retail stores in America. In the case of most department stores and discount stores like Wal-Mart Stores (WMT), Kmart and Family Dollar Stores (FDO), most items cost less than $100, and most stores are very large.