All I can say is:
a) I hope it's really really really popular. Like, every tram crush loaded at peak times so they have to start running more frequently ('cos, you know, can't lengthen trams*).
b) This happens really really quickly, like, 12 months from now, the story that annoying reporter will be quizzing the council on is "Why are your trams so overcrowded?".
Charging what they are for Airport journeys though... I can't see it. Will there be much appeal to commuters beyond the P+R (I've no doubt that will be very successful, but it'll be limited by available spaces).
*Except in Manchester, because we are the best at trams (a double set can carry more than 400 people)