I can't imagine you're getting many buyers if you're asking for 12% over Bitstamp.
Your imagination aside, isn't it much like localbitcoin with a concierge service?
The rates are fairly similar to lbc, and often discounted in comparison. LBC does maybe a thousand bitcoin a day, yes?
If you don't like it, don't use it, or set up your own better service, but I don't see a reason for the disparagement.