It's a little different from the airport to the hotel. They get your flight and hotel info when you make your online reservation and when you arrive you just walk out to the shuttles. They check your name on their list and you get on a van. Yes, they do try to fill up the shuttle, but it rarely takes longer than 5-10 minutes max. You don't have to have a reservation, by the way, but I do it because I like to get the discount and have it paid for ahead of time (you can even prepay the tip, which I always do). I use coupon code UYR59 for $3 off each way. You can get that per person by making a separate reservation for each member of your party or you can try Googling for other discount codes that will get you $2 off per person each way without having to make separate ressies for each. I'm just cheap
ETA: make sure when you do the online reservation that you give the hotel name and not the zip code! The zip code entry will give you a really high rate, like $40 each way. The regular rate if you use the hotel name is $10 each way and with the above code, $7.