what are they, do they help you win competions?

http://www.fantasymarchingarts.com/guide/3
http://www.fantasymarchingarts.com/guide/8

The more influence you have, the better and harder your show can be.

In all honesty, I don't think it matters THAT much.. a lot of people seem to be trying to get a LOT of influence, and they have 10's of thousands of it.. The first 3 seasons I personally only had about 5000-7000 for each group, and was pretty much had the least amount of any group.. yet all of my groups have been in Div 1, and have been in the top 3 every season, some winning gold, and some even going undefeated.