Originally Posted by
flyerhog
I think stamping takes more time than printing a paper and stapling it.
That's exactly right. Consider that it's not just a simple matter of a single rubber stamp. People are admitted to Hong Kong for many different durations and conditions of day. So, the old system was not just a matter of stamping the passport, but selecting the correct stamp to use based on the traveler's nationality, purpose of visit, and so on. The new system has the computer calculate all of this and print the correct information automatically.