Does Amazon crush small sellers underfoot or give them a leg up?

Small businesses, and even some really big ones, have figured out that there’s no beating Amazon. Following the adage “If you can’t beat ‘em, join ‘em,” so many small businesses have joined Amazon’s third-party seller program that close to 50 percent of the units purchased on Amazon now come from third-party vendors. The partnership between Amazon and small sellers is hugely successful, but it’s a rocky relationship fraught with risk for both the vendors and the American economy.