As the holiday shopping season approaches, retailers are competing for attention and ad dollars earlier than ever. Seema Shah shares her take on the trends shaping the retail landscape. She notes that while Black Friday used to mark the start of the holiday shopping season, it's now been pulled forward to October, with Amazon (AMZN) leading the charge with its Prime Days. Shah also points out that despite a pullback in advertising spending by some retailers, big-box stores like Walmart (WMT) and Target (TGT) continue to dominate the ad space, making it increasingly difficult for smaller, mid-size businesses to break through the noise.