Originally Posted by
nightkhan
As Cathay Boy explained it's free if you are MPC Silver, Gold or Diamond, or if you travelled to HK 3 times in a year. However you need to sign up first which is done after going through immigrations in the Arrivals Hall, so to answer your other question, no you cannot use it for a one time entry.
Believe or not, HK immigration officer would not process it when my friend completed his third visit to HK in a year. He said, "Yes 3 times, so next time you can apply." Got up, and he headed out for washroom .....