As for proof that the company won't be disappearing, I am not sure what kind of proof that could be - can anyone actually do that?
Most legitimate companies have more to lose than to gain by disappearing, because of a variety of reasons, the most important one being accountability. Im not yet convinced you could be held accountable if you decide to run one day. But here is a thought, again based on escrow: put a non trivial BTC amount in escrow, to be released to you after x months, or to be used to compensate victims if you turn out to be a scam. In the line of business you're in, you should be able to afford more than a symbolic amount for this.
thank you for your thoughts and suggestions - all is very reasonable and to the point. We will surely look into such possibility.
Meanwhile, we are still in beta, so, need to get some of you guys to try the service and share your thoughts - what is good, what needs to be changed, etc. Doing that on small amounts - there is no risk for anyone. After all, we have our risks too, especially once the 'buy' functionality is enabled and users are allowed to buy BTC using credit cards (this alone could be worth a separate topic!)