Being new with no feedback makes sellers nervous.
Specifically addressing this valid hurdle... I can only speak for myself.
1) My first trade was in person, and that person left me feedback, so that helped establish at least some history. To be honest,
that's how I found out about iTrader.
2) I was a pretty well established DGCR regular by the time I started dealing - I think it helps if people get the feeling you've been here for a while and they've read a few of your posts and at least have some sort of feel for who you are. Granted, it's not much, but as you read someone's "body of work" over a period of time, you get a feel for how they conduct themselves.
3) When selling, I don't ship until the payment hits my PayPal account, so it honestly doesn't make a difference to me if a Buyer has zero feedback. They pay --> I ship next day. No money, no ship.... I have nothing to lose. The trust is on the part if the buyer. But since I've at least had some solid feedback (admittedly not much), combined with a history on the site, at least they have the reasonable expectation that trust isn't misplaced.
As a buyer, I expect the same, so I won't send a payment to someone with zero feedback, unless I actually know them or (i.e. not just on the interwebz, but I've actually met the person somehow) or theyve' been here a good long time, because I really don't know squat about them.
And obviously, PayPal just makes the whole thing a lot easier.
Trading's a bit trickier. I want to see some solid feedback before dropping disc in mail on a trade.