You can't advertise to the general public. It moves the FAA paperwork from section 5 to 6 and that requires a lot more paperwork, security, first aid plans. You CAN advertise to MEMBERS and since the IAC is "owned" by the EAA, you could easily invite EAA members. But the EAA does not. In fact, this year they pretty much have put barriers in place to prevent spectators.