Tinkering with the core mechanisms of the world's busiest e-commerce site is not something to be undertaken lightly. Yet John Donahoe, head of Ebay's marketplace division, is preparing an overhaul for early next year that amounts to a major revamp of Ebay's core business.

If successful, it could revive the company's flagging growth while also strengthening his own standing as the likely eventual successor to Meg Whitman as Ebay's chief executive.