Do these sell out if you dont buy them online in advance enough. Just wondering. They seem popular. I know you can get them at the park but I heard its better to buy on line along with the tickets.

Which Universal?? California or Orlando??
It depends on the time of the year. If you go off season you don't really need them.

During peak times, you do need the Fast Pass...worth every penny...and buy then as far in advance as possible. If you are going during off season and during mid-week, you probably don't need to spend the extra money.

This doesn't answer your question, but...

in Florida, we usually book 1 night at one of the Universal hotels. Then, we get fast pass for free for the 4 of us and we can use it for 2 days.

Not sure if that deal is always in effect, but we've done it a few times over the years.

Fast pass is really wonderful.

With the hotel deal, you can have up to 5 people in the room, so you can get 5 fastpasses.

We are going to Orlando during the week of xmas. I was concern should I go ahead and purchase the tickets now. I heard its busy there at this time. I cant see standing in line for no 1 or 2 per ride.

I agree with travelgirl2 - if you can stay at one of the onsite Universal Hotels - Portofino Bay, Hard Rock Hotel or Royal Pacific, your room key will act as your front-of-the-line pass at the parks beginning the day of your arrival through check-out day.

It is a fabulous perk. We've done it many times. If you are going at Christmas, crowds will be heavy and lines will be long.