The platform is in live mode. Anyone can register right now and trade or buy items of their choice.
Actually, you may even try some of your stuff to sell to someone you know to test the platform.
How do we know the other party is reliable? The reputation system only works after people shared their experience. That means the first people to start trading have to take a gamble. As far as I can see it is trivial for a fraud to pretend to be a company selling products. How did eBay and Alibaba pull this off?