So apparently Blackbird is just the "marketplace" for planes that are available for rental or lease, and the renters need to employ a qualified pilot to fly, conveniently located through the list of qualified pilots associated with each plane.
They also say that you can "share" available seats with other Blackbird community members, but the rules prohibit charging those additional passengers for travel.
Totally sketchy arrangement. Totally convoluted way of using Part 91 rules to do Part 135 flying. They blatantly "hold out" to the public in their advertising. Customers have no idea what they are getting into.
It won't end well.