Editor's Note: 5 Cross-Channel Retail Trends to Watch in 2012

4. Online marketplaces grow beyond Amazon. Based on the success of Amazon, retailers will begin to understand that offering their products in marketplaces other than their own website is critical to driving up margins and remaining competitive. Retailers in verticals such as apparel, toys and sporting goods, in particular, will continue to build their own online marketplaces to retain some of the market share they may otherwise lose to Amazon.