Whoever makes an equivalent site may take a huge market share away from Ebay once Ebay wakes up and decides to be a part of the Bitcoin movement.
Its going to take a big site to take away any of eBay's market share though. And once they see it happening, they could squash the competition pretty easily, buy them out, OR start taking BTC. I know the CEO of PayPal has mentioned it several times in interviews. I think its def. on their radar
In fact, the CEO of eBay has mentioned both eBay and paypal will accept bitcoin.
http://www.ibtimes.com/paypal-getting-bitcoin-ebay-ceo-says-digital-currency-integration-coming-very-soon-1594904I think theres no doubt digital currency is going to play an important role going forward, and at PayPal, were going to have to integrate digital currencies into our wallet, Donohue told CNBC.
He didnt give a specific start date but said that bitcoin will slowly be integrated into eBay and PayPal services, starting with peer-to-peer transactions and international transactions. Eventually, merchants on eBay will be able to accept payments in bitcoin.