The time in the air also helps the cue ball lose any side or english momentum it may have to go straight forward instead. The best way to think of this shot is "If I nudge the cue ball off this chalk and forward on line a few inches, it will roll forward due to momentum and sink the eight ball."
Nice and easy does it--and causes the cue ball to travel slowly enough to build some suspense for the audience (and you, the hopeful trick shot artist).
