The Spirit Award is awesome. Spirit was a very big part of my experience in FIRST when I was a student. Cheering, dancing, spreading wacky spirit in the pit...it was something that I could contribute to, considering my limited technical skills at the time. Spirit was something very present in the culture of the team, both at the events and at our meetings. We wouldn't always have the best robot, but we could give you a run for your money in the spirit department.
It's already been said, but I agree that spirit is more than just being loud for your team, it's about the overall enthusiasm you bring to the competition and beyond. I think this is what FIRST was originally looking for when they created this award. Sometimes it's a bit disappointing to see a team with a great robot, great business plan, but absolutely zero enthusiasm because to some, the Spirit Award is just not that important. I think they're missing out on all the fun.
And it's not just about cheering for your own team, it's more about cheering for FIRST. The events are not just a competition, but a celebration of 6 weeks of hard work. Have fun, regardless if there's an award in it for you or not.