In a modern fairy tale, the smart little pig would have built his house out of e-commerce, since it’s apparently much stronger than bricks. Brick and mortar retailers like Best Buy, Hhgregg, and Radio Shack are seeing sharp declines in profits as more customers shop online. Last week, shares of Hhgregg plunged 30 percent when the company had to cut their full year forecast.  The news also affected...