Forget Main Street: This industry is composed of retailers with no physical retail presence. Instead, they sell solely online -- and are especially thriving in the areas of quality handmade jewelry and vintage clothing.

After Web retail saw revenue fall as the recession decimated 2009 sales, expectations are high this year. The industry has a remarkably low barrier to entry: Have something to sell? Get a PayPal account and you are set.

Online sales of independent merchants - mostly via sites such as Etsy, eBay, RubyLane, and Supermarket - grew at an annual 6.6. percent over the past five years, according to IBISWorld.

By the numbers:

Number of Americans who participate in the virtual retail marketplace, according to IBISWorld: 100 million

Percent the economic slump hit revenue for e-commerce and online auctions in 2009: 4.8

Expected rebound of e-commerce and online-auction sales during 2010, according to IBISWorld: 7.8 percent

Anticipated annual growth rate over the next half-decade: 10.5 percent