From the growing importance of mobile to changing expectations about free shipping returns, here are key developments in retail.  In order to thrive, retailers should pay attention to mobile, the retail store itself, location targeting and other key developments. During this past holiday season, online shoppers set records on Thanksgiving Day, Black Friday and Cyber Monday, shelling out more than $5 billion. That's up 22 percent from the same period in 2012, according to IBM's 2013 Black Fr