Revenue is expected to grow 31.9% to $6 billion in 2013. "Rising demand for social network-based games creates opportunities for potential industry entrants. Additionally, widely available industry associations like the Entertainment Software Association can help new entrants by providing market research to develop more highly in-demand products," the report notes. 2. Online Shoe Sales Online shoe sales have benefited from consumers flocking to the Web to purchase goods and services online. Shoe sales online alone are expected to grow at a "robust" 16.2% five-year annualized rate to $8.9 billion through 2013. The report cites a survey by Nielsen indicating that clothing, accessories and shoes are the second-largest category of items behind books that consumers purchase online. "With such rapidly increasing demand, traditional brick-and-mortar retailers have an opportunity to enter the online realm and recapture sales taken by retailers that operate exclusively online," the analysts write. "Although new industry entrants face competition from well-established incumbents, this threat to success is partially mitigated by the industry's fragmented nature." Currently the industry's two largest players -- Amazon and Foot Locker ( FL) -- control less than 16% of the market. However, new entrants will need to differentiate, with either a unique product line or non-traditional strategy to drive traffic to their website. 3. TV and Home Theater Installation Services The TV and home theater installation services industry is "highly fragmented," IBISWorld says. Yet with a low level of capital needed to start a business, those with transportation and proper tools can easily enter the industry. In order to be successful, though, startups must "keep up with the rapid pace of technology in the industry," the report says. With 98% of today's households owning at least one television and 84% having at least one DVD player and another 25% that have home theaters, the industry has expanded rapidly. Revenue rose on an annualized basis of 4.1% to $12.2 billion over the five years to 2013, according to IBISWorld. 4. Virtual Data Rooms Virtual data rooms provide clients with secure document sharing and storage services geared toward legal due diligence, mergers and acquisitions, initial public offerings, bankruptcies and other information-sensitive applications.