Charge for Wifi on top of your plane ticket? Yeah right.
Add 20p to everyone's ticket and give it away, or don't bother at all.
And 75Mbps (presuming asymmetric) shared between 200 passengers, their phones (whether active or not), tablets and laptops is basically pointless. It's like 200 people sitting in your living room trying to all connect at the same time.
No way would you ever get a stream going. And that's even more reason for people to NEVER pay for it.
Seriously, people, this is 20 years overdue and still naff.