Each of these need to reach a certain number of ticket bookings by the deadline to become confirmed - this is called the Tipping Point. So you will see some are confirmed and some are not. When a screening reaches the Tipping Point everyone receives an email telling them the screening is confirmed. If this doesn't happen by the deadline everyone is automatically refunded - so there is no risk. If everyone buys a ticket and tell their friends to do the same, more screenings will happen.