bitbay,
We've been operating BTX Trader for the past six months with thousands of users who have linked their exchange accounts via API keys.
We are backed by a NASDAQ-traded public company (WPCS).
We're adding some testimonials to the site soon we well.
What kind of security do buyers have? I mean here, people use really old trusted escrows to purchase/sell bitcoins. So how can a user trust you, that if he sends money to you, you will send him bitcoins? Would you trust a stranger by sending him bitcoins first?