I was at a mountain in lake tahoe that did this (Sierra at Tahoe). Season pass holders had a seperate line, and at the front of the line was a gate, u put your little module on the pass up to a sensor, and the gate opens, thus tracking your vertical. What was cool about this program was, based on your vertical they gave you comp dollars to use at the pro shop and stuff. I was talking to a dood who was saying he broke a pole while skiing there, so he went in and redeemed his "vertical points" for new poles . Quite a good incentive to draw in season pass buyers in a competitive area with a bunch of ski resorts.